I don't describe my music in terms of favorites, but rather in terms of ratios. I'd say my listening choices are about 70% instrumental and 30% more contemporary music. Game soundtracks comprise a large portion of my playlists -- in fact, I have several albums of nothing but Zelda music, one exclusively for Chrono, and another for general Squaresoft music. I also like older, more baroque music, especially when it's applied to modern media -- the songs from Symphony of Evangelion are classical and baroque, such as Pachelbel's Canon in D, Ode to Joy, and the Hallelujah Chorus among others. Salvation is Created by Russian composer Pavel Tschesnokoff is another favorite of mine -- it's the warmup song of the marching band of the high school I just graduated from. We didn't play it all season last year, but we broke it out at the state finals -- my best friend and I cried at that point, and even moreso when we won. Hit me up on AIM for it if you want. In fact, I demand that you do so if you haven't already heard it. As I play the clarinet, I'm a bit biased in favor of it. Mozart is good for woodwind-type music. I'm not that into Vivaldi -- the (IMO) greater fullness and complexity of Tchaikovsky and Stravinsky are more my speed. Stravinsky's The Rite of Spring is one of my favorite songs, and if you play RPGs with any frequency it should be one of yours as well -- Nobuo Uematsu has stated the obvious in saying that Final Fantasy VII's spectacular One Winged Angel was based on it, and the stylistic resemblance is easy to hear. Holst's The Planets is another good piece of work, as is Wagner's Ring cycle -- the previous four composers' ideas taken together is basically what comprises the score of the Star Wars saga, which anyone who's been on these boards for more than five minutes knows I'm kinda crazy about. Other film composers like Danny Elfman and Hans Zimmer use basically the same cues over and over again, but at least they're good cues.
As far as more contemporary music, I like a fair amount of older music, including the Beatles, Aretha Franklin, Barry Manilow, and even Gloria Gaynor -- gotta give her the props for "I Will Survive." Sinatra's great, too -- he deserves all his accolades. A bit of ethnic music is also good when done right, as the scores of The Lion King, the Donkey Kong Country series, and Star Fox Adventures, which rules no matter what you say, illustrate. Chrono Cross does some of this as well, most notably during the battle with FATE -- which doesn't make a lot of sense considering that FATE is an immensely powerful supercomputer from the 25th century. You'd figure on some kind of techno being played, but instead they go with pan flutes and ethnic drums while it tries to Ctrl+Alt+Del you out of existence. Wind band is another contemporary style of music -- Frank Ticheli and Eric Whitacre are currently the kings of that genre. I've met Frank Ticheli before, and two of my friends, both All-State drummers and fellow geeks, have met Whitacre. Ticheli's Vesuvius is, IMO, the ultimate head-bang piece for the wind band genre, doing for it what such groups as the Smashing Pumpkins and Slipknot do for thrash metal. I also kind of like Breaking Benjamin, both for So Cold and Blow Me Away, the song from Halo 2 -- kinda goes against my principles, but they both rock. The Metroid Prime series is an excellent example of what techno music should be. Weird Al Yankovic is hands-down my favorite contemporary artist. A little side fact: despite what you may think of his songs, he is a highly intelligent man, having graduated valedictorian from his high school class and being possessed of a degree in architecture. Guns N' Roses is a great 80s group. Mega Man X fans take note here: the song "My Michelle" sounds almost exactly like the music for Neon Tiger's stage in Mega Man X3. This is no doubt intentional, as all of the bosses in the American version of the shortly proceeding X5 are named after members of the band. Yellowcard is the closest thing to a pop band that I like. When I'm feeling emo, I turn them on and proceed to write random crap that doesn't make any damn sense at all. Finally, Trey Parker and Matt Stone, in addition to being accomplished writers of satire, are also excellent musicians, having written and performed every South Park and Team America song themselves. The crew of Monty Python also falls into this category. Jeremy Soule is the last artist I can confidently name, as he composed the scores for two excellent games, Morrowind and Knights of the Old Republic. He has even submitted some of his work to OCR, lending it a bit of credibility by garnering support from such a highly regarded musician.