Seems a somewhat generic and vague category, but: Music, movies, illustration, graphic design, web design, comic books, concerts, subjective fashion, tattooing, piercing commercial advertising, exercise, sleeping, women (see previous 2 interests), video games, philosophy, government and politics, medieval culture, and modern law.
I'm in to most every form of music, mainly rock and the local scene though. I also can't claim to have the largest interest in country, then again I don't seem to know anyone that does.
Bands I like, in no particular order:
Sims, Atmosphere, American Head Charge, P.O.S, Cold, Killswitch Engage, Dessa, Brother Ali, Korn, Matchbox Twenty, Metallica, Disturbed, Green Day, Eyedea and Abilities, Sevendust, His Infernal Majesty, Non-Prophets, A Fire Inside, Cecil Otter, Nirvana, Slipknot, Mudvayne, Sage Francis, Immortal Technique, Rage Against the Machine, Audioslave, Stone Sour, Hed (P.E.), Gingerjake, Mindless Self Indulgence, Smilin' Liar, Ant, Snoop Dogg, Marilyn Manson, DMX, the Green Mushrooms, Instant Legend, Tool, Alice in Chains, A Perfect Circle, Lupe Fiasco, Sublime, Maroon 5, Lost Prophets, Incubus, Finger Eleven, Richard Cheese, Flaw, Nine Inch Nails, CKY, B.B. King, Eric Clapton, Soomon Burke, the horror music scene, and quite a few others that I won't take the time to list at the moment.
Hackers, Underworld, Mallrats (and any other Kevin Smith film for that matter), The Nightmare Before Christmas, Liar Liar, Edward Scissorhands, Scooby-Doo 2 (first one was terrible), Spider-man, Spider-man 2, Cruel Intentions, Batman, Requim for a Dream, Harold and Kumaar go to White Castle, Pirates of the Caribbean, the Life of David Gale, Se7en, Saw, Friday the 13th part 2,3,and 7, Eternal Sunshine of the Spotless Mind, Clockwork Orange, the Dead Poets Society, The Breakfast Club, Tombstone, The Teenage Mutant Ninja Turtles, The Crow, Resevoir Dogs, Fight Club, Interview with the Vampire, Aladdin, Kill Bill, Evil Dead, Pulp Fiction, Sleepy Hollow, Queen of the Damned, Death to Smoochy, Horror movies of all kinds, and so very many more.
Invader Zim, The Simpsons, That 70's Show, Law and Order, Family Guy, The fine people over at Comedy Central, Adult Swim (mainly for Futurama), CSI, The West Wing, and occassionally some general Cartoon Network.
Neil Gaiman's Neverwhere, Good Omens and Sandman series, Stephen King's catalogue, Nietzsche’s Beyond Good and Evil, William Blatty’s Exorcist, Anne Rice’s Interview with the Vampire, H.R. Giger’s Necronomicon, Greg Pak’s Phoenix: Endsong, Straczynski’s Blood ties, Douglas Adam’s Hitchhikers Guide to the Galaxy, and Todd McFarlane’s Spawn. Also, C.S. Lewis and Orson Scott Card.
Greg Cappulo,Jeff Hubbard, Nietzsche, Todd McFarlane, Jim Carrey, B.B. King, Jhonen Vasquez, Glenn Beggin, my father for putting up with me, and Ben down at the tattoo shop.