Syfy

1st Logo (September 1992-1998)
Unknown.

2nd Logo (1993)
Visuals: Unknown.

Technique: Live-action for the grandfather clock, and possibly CGI for the monster.

Audio: The sounds of the clock accompanied by a creepy theme, followed by a voice saying "You are watching the Sci-Fi Channel" and a woman's scream.

3rd Logo (1998-1999)
Unknown.

4th Logo (UK only) (1999-November 2002)
Unknown.

5th Logo (2000s?)
Visuals: These are actually a series of idents that played during subsequent commercial breaks during the same show. They focus on invading, carnivorous alien plants that eat anything that happen to get in their way. For example, one ident shows a bird being eaten and the final ident contains a human hand being eaten.

Technique: CGI.

Audio: Unknown.

Legacy: The subject matter in these idents can creep some people or at the very least, scare some.

6th Logo (December 2002-June 2009)
Visuals: A varying series of IDs that show fantastical and often whimsical events playing out, of which they end the same way: The screen is covered by many transparent surfaces of shades, turning the entire area into a brightly-lit  room with a curve in the bottom right similar to Saturn's rings. The new logo, which is an simplified version of the Saturn from before in white, flashes in, as well as the text "i F". The rest of the text fades in, forming "Sci Fi" in a custom font. The following known IDs are as follows:
 * A toddler appears to yawn at the camera, but then starts to breathe fire, melting the camera’s lens.
 * A woman is approached by a fantastical, Sphynx cat-like creature that she apparently keeps as a pet. She picks the creature up, and the two of them touch tongues.
 * A black pickup truck drives in front of the camera. After it parks, it begins to shrink and disassemble, revealing the woman driving. When the truck finishes disassembling, it turns into a small, key fob-like object, which chirps twice and goes into the woman’s purse.
 * Two men, one dressed in red and the other in green, are shown playing ping-pong against each other. As the camera pans across the ping-pong table, we see that the two players each have six arms. The man in green hits the ball too fast for the man in red to be able to hit it back, and the man in green raises his arms in victory.
 * A woman reaches towards a rose, pricking herself on a thorn. She is shown to panic, as water begins leaking out from where she touched the rose. Zooming back to the whole room, she pops like a bubble.
 * A man is shown breakdancing to hip-hop music, and he appears to be spinning his entire body in different directions. We zoom in on the man’s head and we are shown that he is actually turning his head around 360 degrees.
 * Multiple groups of identical-looking men appear to dance around. At the end of the ID, two of the men look at each other and nod in identical ways.
 * A woman is shown laying down and breathing smoke into the air. The smoke begins to resemble a human in shape, and the woman brings the smoke being closer to her, presumably to kiss.
 * A blue butterfly is shown to land on the hand of a woman in a red dress. When the butterfly flies away, the woman transforms into a swarm of butterflies that follow the blue butterfly.
 * A balding nude man pulls on one of his hairs, and notices that the hair seems to go on forever. As he continues to pull on the hair, we see that he is literally unraveling as he does so.
 * A large crowd of monochrome office workers is seen walking through a narrow corridor, starting to get overwhelm that he cannot walk through the crowd. Desperate, he starts to run up and grows a pair of metallic wings, flying out of the crowd as they look in awe.
 * A old gardener is finishing up clipping a hedge sculpture of an elephant when it starts to shake and come to life, pulling itself out of the ground as it trumpets in his face. The man laughs as he pets the trunk.
 * A shot of a dark forest in in view, as a ominous hooded figure lumbers forwards and lightning strikes. The cloak then reveals a grouchy-looking cartoony monster is actually inside, and the cloak is pulled off, revealing that the figure is actually 4 of these creatures as they hop off and go in different directions.
 * A woman is shown putting on a loose-fitting, leopard-spotted dress and looks disappointed. However, the leopard prints starts to appear all over her body as metallic ribbing forms over it, creating a more interesting jumpsuit as the woman smiles in approval.
 * A man is shown juggling pins and a blue ball in an empty circus setting. The man then starts to pull off his head and juggles that with no harm, and then his leg as he is shown starting to lose his balance.
 * A performer pulls up a dog and starts to blow into its rear end, slowly turning it into a living balloon dog with each blow. With the final blow, he shows it off, but the dog kicks him off-screen in anger.
 * A shirtless man is seen dodging various different devices, shuriken, and darts Matrix-style. He then seemingly creates a wall of nothing in front of him, blocking a bunch of projectiles as it shatters like glass.
 * A strange fairy-like boy flies around and sticks to the screen, with large eyes and sucker-like fingers and toes. The camera cuts to a close-up to his face, speaking a strange language he does, before he flies away.

Variants:
 * Starting around 2005, the logo instead ends with "iF" fading in first before the screen is covered in a translucent version of the background, and the text spaces apart a bit before the rest of the logo fades in.
 * Sometimes, the ID is shortened to a few seconds and a dark purple series of curves appears at the bottom of the screen, with the logo forming from within.
 * Later on in 2007, the "iF" would appear in the middle right, before a burst of white smoke is released to cover the screen and form a cloudy background, with the full logo appearing then. The IDs are also in a letterbox format, with the bars colored.

Technique: A blend of CGI and live-action footage.

Audio: Depends on the ID, but it always ends with a 3-note synth pad tune with added string plucks.

7th Logo (2007-June 2009)
Visuals: A series of IDs, all of the taking place on a cloudy background filled with light blue spots, and "iF" is seen on the middle right. Something or someone touches the "iF" and something whimsical happens, of which the Sci Fi logo is formed from smoke as clouds start to appear. The IDs are as follows:


 * A plastic bag flies in front of the word “iF” before touching the “i” in the word. When the bag touches the “i,” the “iF” transforms into the Sci-Fi logo, and the plastic bag turns into a brown-haired woman in a flowing white dress who floats into the distance.
 * A little boy waters the “iF” with a gardening hose, changing the “iF” into the Sci-Fi logo, and causing a giant beanstalk to grow behind it. The boy looks at the top of the beanstalk in amazement, but is soon crushed by a giant’s foot coming from above.
 * A sumo wrestler runs towards the “iF;” when he reaches it, the “iF” changes into the Sci-Fi logo, and he is blown back and transformed into a crowd of miniature wrestlers wearing luchadore masks, who all scatter and disperse.
 * The “iF” is struck by lightning, changing it into the Sci-Fi logo, and cats and dogs begin to rain down from the sky.
 * A woman in a pink dress carrying a small dog in her handbag approaches the “iF,” and attempts to give it a kiss. When she kisses the “iF,” it changes into the Sci-Fi logo, and the woman is changed into a large frog (still wearing the same dress) as the dog runs away.
 * A man in casual dress touches the “i” of “iF,” turning it into the Sci-Fi logo. The man reaches to the back of his head and begins unzipping his skin, revealing a woman in a white skirt underneath.
 * A computer-animated baby touches the “i” of “iF,” turning it into the Sci-Fi logo, and giving the baby improbably large muscles. The baby beats his chest, and moves away with his muscular arms.

Technique: A blend of CGI and live-action footage.

Audio: Depends on the ID, but they share a common musical motif: a 4-note pizzicato string melody as the "iF" is approached, building to a climax after changing into the Sci-Fi logo. Some variants have different variations on the melody; for example, the sumo ID has its music played with flutes and xylophones, and other variants feature variations on the ending theme (the frog ID ends with a trombone melody, and the skin zipper ID ends with a playful, percussive melody)

1st Logo (July 2009-June 2017)
Visuals: A series of IDs, each with a unique number of materials either forming or being released from the Syfy logo with the channel catch phase "Imagine Greater" under the channel name, The IDs are as follows:


 * A number of varied sized purple liquid blobs bounce into the shape of the name "Syfy." The logo then lights up while a single blob bounces away from the name.
 * Triangular pieces of paper both white and purple grows as it form the name "Syfy." A single origami butterfly then flies away from the logo.
 * Yellow flowers covering the name "Syfy" are blown away from the logo.
 * Colorful string, confetti, and square shapes burst out of the Syfy logo and then quickly remark back into the Syfy logo.
 * A purple liquid sloshes around to form the Syfy logo while a single droplet rises upwards from the first Y.
 * A number of flying glowing white wings frolic around while the Syfy logo forms and rises to trap the white wings until only a few wings are released from right corner of the last Y.
 * White and Pink balloons are inflated into the shape of the Syfy logo with small fragments of balloon being blown away from the logo when fully inflated.
 * Gear pieces turn and move into the shape of the Syfy logo.
 * A collection of till colored marbles fall and form into the Syfy logo with three remain marbles being ejected to the side.

Technique: CGI by ManvsMachine.

Audio: Depending on the ID, a jingle is included usually 3 notes drawn out. Sound effects overplayed based on the materials in each ID.

2nd Logo (2015)
Visuals: Basically it depends on the ID, and it's hard to describe in detail, but here's the concept: Something Halloween-related will appear at the start (cards, a baby doll, a grim reaper, a huge mantis-like bug, etc.) Then, some of these will remain showing briefly, until we cut to a dark background with /white cards, the word "HALLOWEEN" in a creepy font with "W E E K" under it and the "O"'s hole filled with black and containing a skull, and a bug walking in the down-right corner. Then the scene flashes to the Syfy logo on a card with two other cards on the left and right (both are white), with one containing the skull and one containing a flaming circle. A huge Madagascar hissing cockroach walks on top of the setting. There are three idents in total.

Technique: Live-action.

Audio: A bunch of Halloween-related sounds, such as a creepy music-box stinger, droning sounds, and sounds corresponding to the subject matter. The ending of these idents always have a 2-note stinger.

Availability: They were only used during October 2015.

Legacy: The extremely dark atmosphere, some of the sounds, and the cockroach at the end (not to mention the effect that it will have on people that are scared of bugs) can terrify many viewers, though these are intentional due to the fact that they were aired on October.