It varies, but to name a few:
Being compulsive,
Antagonism as a sport,
Making other people crack up laughing,
Making myself crack up laughing,
Political philosophy,
Religious philosophy,
Friendly debates,
Unfriendly debates,
New challenges,
Devious adventures,
History,
Renewable Energy,
Green Building,
Spontaneous travel,
Lucid dreaming,
Consuming useless trivia,
Spewing out useless trivia,
New ideas,
Insane ideas,
Scrabble and most other board games,
Poker and most other card games,
RPGs and other video games (except 1st person shooter games - they're boring),
Crossword puzzles,
Surrealist art,
Museums,
Jazz clubs,
Corporate ethics,
Salvador Dali,
Nothing,
Everything,
Sarcasm,
Revenge,
Mischief,
Living in my glass house,
Falling off my high horse,
Being judgmental to practice good judgment,
Furtling,
Hating Scientolgists
People that are smarter than me, nicer than me, funnier than me; which, mind you, is no easy feat.
..
Aquabats
Bach
Beach Boys/Brian Wilson
Beatles
Beethoven
Blonde Redhead
Brazilian Girls
Cake
Cat Stevens
Charlie Parker
Clyde McPhatter
Crystal Method
CSNY
David Bowie
Death Cab for Cutie
Doors
Duke Ellington
Earlimart
Ella Fitzgerald
Elvis Costello
FC
Giant Drag
Harry Connick, Jr.
Herbie Hancock
Jet
John Coltrane
John Lennon
Joshua Redman
Led Zeppelin
Lenny Kravitz
Michael Crawford
Miles Davis
Muse
Neil Young
Nirvana
Offspring
Pearl Jam
Philistine/Loma Lynda
Pink Floyd
Portishead
Postal Service
Primus
Prodigy
Queen
Radiohead
R.E.M.
Rilo Kiley - Everything except UTB
Siouxsie and the Banshees
Stereolab
Stevie Ray Vaughn
Strokes
Tenacious D
The Music
They Might Be Giants
Tom Petty
Vivaldi
Yeah Yeah Yeahs
Zappa
I'm obsessed with documentaries.
A Patriot Act
About Schmidt
Adaptation
American Beauty
American Splendor
An Inconvenient Truth
Being John Malkovich
Best in Show
Better Off Dead
Borat
Bottle Rocket
Breakfast Club
Breakfast on Pluto
Chasing Amy
Defending Your Life
Eternal Sunshine of the Spotless Mind
Fahrenheit 9/11
Forbidden Planet
Fun with Dick and Jane
Garden State
Gattaca
Happiness
High Fidelity
Idiocracy
Invasion of the Body Snatchers
Little Miss Sunshine
Lost in Translation
Man on the Moon
Monty Python
Munich
Napoleon Dynamite
Outfoxed: Rupert Murdoch's War on Journalism
Pi
Punch Drunk Love
Ringers: Lord of the Fans
Rushmore
Saved!
Sicko
Spanglish
Spellbound
Supersize Me
Teeth
The Day the Earth Stood Still
The King of Kong: A Fistful of Quarters
The Life Aquatic with Steve Zissou
The Lives of Others
The Royal Tenenbaums
This Boy's Life
This Is Spinal Tap
Thumbsucker
Welcome to the Dollhouse
Who Killed the Electric Car?
Why We Fight
And of course, everything listed here
Antiques Roadshow
Boondocks
Bridezillas
City Confidential
Countdown with Keith Olbermann
Curb Your Enthusiasm
Da Ali G. Show
Entourage
Futurama
Hardball
Modern Marvels
Seinfeld
Sex and the City
The Apprentice
The Daily Show
The Simpsons
The Sopranos
X-Files
Authors:
Ayn Rand
Thomas Pynchon
Hermann Hesse
David Foster Wallace
Kurt Vonnegut