This excludes UT2004 (not UT though!) level music and the BW soundtracks (sorry SB...), I mean like normal songs. Example: my own list below:

The Final Countdown - Europe
This Fire Burns - Killswitch Engage
Thunderhorse - Dethklok
Free Bird (solo) - Lynyrd Skynyrd
Beast and the Harlot - A7X (Avenged Sevenfold)
Towards Dead End - Children of Bodom
Lake Bodom - Children of Bodom (fav!!)
Skedar King - Rareware Ltd.
Through the Fire and the Flames - DragonForce
My Spirit Will Go On - DragonForce
Fury of the Storm - DragonForce (god......... so.... fast.... @_o)
Jordan - Buckethead (whoo! kick-ass solo of hell!)

I listen to the Halo and Halo 2 soundtracks, Godsmack, Blind Guardian and Disturbed when fragging bots with the G5 alt fire.

I disabled the default UT2 music because it is crap, but this gives me the idea to try use my playlist.

Oh you mean't through the UT2k4 player. Well then non, cause i listen to that stuff (above) from my Ipod which is connected to this Bose player.

The in-game player only supports MP3s that have empty ID3 tags, so I'd rather want to just run a music player in the background like XMPlay or WMP since I use ID3 tags heavily.

Personally, I think either Ambient music or Drum'n'Bass/Jungle fits with this game.

Maybe it's cause I'm into that type of music, too. Regardless, I'm really against lyrics when it comes to action games.

I don't think i can do it but if i did i'd have,
Bodies By Drowning Pool
and my fave

Welcome to the black parade by MCR (my Chemical Romance)

Nah, it doesn't need to be through the UT2k4 music player. I use that yes, but you can use anything you want for your music. It's not like I just said only songs in UT2004, I mean to say not the UT2004 songs themselves.

All albums of Mudvayne, some Mushroomhead, and alot of Linkin Park. Also a little sprinkle of Avenged Sevenfold and other bands.

Mudvayne and Mushroomhead pumps a lot of adrenaline into me.. especially Determined from Mudvayne.

If you want my full list of every single song I listen to (Yeah, like anyone wants to see that.), I will happily post it up.

Eiffel 65
ShadowBlade's AWESOME music
EnteR's AWESOME music
My own mixes
Rednex's Cotton Eye Joe
Europe's Final Countdown

I listen to whatever is playing on the map. Some songs are quite nice, especially some custom ones.

I listen too my songs +
Through fire and flames - DragonForce
Operation Ground And Pound - DragonForce
Run To The Hills - Iron Maiden
Polkarama! - Wierd Al Yankovic
Revolution Deathsquad - DragonForce
Duality - SlipKnot (The only good song from SlipKnot
everything else... SHIT!!!)
Bring the Noise - Anthrax Feat Public Enemy (YO!)
Angel Of Death - Slayer
Inspector Gadget [Techno Remix] - Scooter
Xavious & ShadowBlades music
And more DragonForce...

PainKiller soundtrack in zombies invasion, a killer!

Check out Red Harvest. They're sort of like an aggressive metal/industrial type of thing, it fits with the whole futuristic war thing well.

Disturbed,
Rammstein, (Morgenstern especially makes the round sound epic!)
Tool,
a lot of TimeSplitters music,
some Perfect Dark 64 songs,
and the random Katamari Damacy song thrown in to lighten the mood!

Almost forgot one! Anyone here ever heard of Machinae Supremacy? They're a cool metal/electronica band that actually sounds a lot like video game music, only BADASS!

...or Mann Gegen Mann, epic with a gay twist.

Anyway, I listen to all sorts of stuff, though mostly dance/trance/techno (mellow, with female vocals)
Some current examples:
Anaconda - Time Has Come
Technorocker - Power Of Love
Danielle Paris - I Can't Stand It
East Clubbers ft Kate Leasing - It's A Dream
Alex Megane - I Think Of You
Etc.

But also:
Irish Rovers - Christmas In Killarney
Mika - Grace Kelly
Koto - Visitors
Air - Sexy Boy

And of course some of the better custom UT music, including SB's stuff.

I haven't heard Mann Gegen Mann yet. Links, 2, 3, 4 sounds pretty cool in Onslaught, with the marching troops and shouting.

I used to listen to my own playlist, but I got bored of it, so I'm back to stock UT2004 BGMs...

Sonic Mayhem
Shawn McPherson - Taste the Blood
Union Underground - Across the Nation
White Zombie
Yngwie Malmsteen
Steve Vai
Metal Gear Solid BGMs

Ok, I reached the conclusion that some Alice Cooper hits are very good with UT2, at least my ears think so.
Hint: Hell is Living Without You and Feed My Frankenstein.

As I listen mostly to melodic / power metal I usually prefer not to listen to my regular music collection when playing UT, lyrics and complexly arranged songs tend to get too distracting when playing high-speed games that rely on fast reflexes. Exeptions are Clawfinger, In Flames and sometimes Manowar, the first two are very straightforward, rough and ass-kicking, while Manowar is just motivating, can't really say why...

Didn't try Youtube yet? Here it is, found it right away: http://www.youtube.com/watch?v=fF-ReJD6MmY
Sensitive minds be warned, though, the video can be quite disturbing, that's intentional. All who can understand the lyrics will know why the video is like it is. Just let me say that Mann gegen Mann (translation: "man against man", or "mano a mano", as they tend to prefer the spanish version in the movies) has nothing to do with fighting...

If you love metal, you'd love Mudvayne's math-metal/nu-metal style. Their songs actually have MEANING to it, like how Choices is about the powerful people who take away from people who are less fortunate and leave them no choice but to comply, and -1 is about the people who treat you like you are less than nothing, which is why I listen to them when playing UT2004, because I imagine the bots are these individuals who insult you, and it motivates me to pop their heads.

Don't deep meanings just make you less concentrated on the gameplay flow?

Not exactly, I play efficiently even with that kind of stuff, because if the meaning promotes the objective of the game, it all fits together.

I thought only women wanted a meaning to everything. I just kill to get frags and win the match.

Not a meaning to everything. It's like getting pshyched up for a match, at least for me.

I know a fair amount of German. Besides, it's not like Mann Gegen Mann is their most disturbing song (Buck Dich's video was screwed up, and Zwitter was just messed up in general (Zwitter = Hermaphrodite)).