I'm not sure how many people have UT2004 but lately i have been looking through the mods and found some rather good ones. Note: many of these mods are still in beta stages and there are still bugs.
Red Orchestra - (5/5) - the most well known mod, based in WW2 on the eastern front. http://redorchestramod.gameservers.net/
Deathball - (4/5) - team ball game loosly based after football(soccer) http://www.deathball.net/
Carball - (4/5) - Like deathball except in buggies, with powerups. http://nzue.skankyflat.net/cb/home.htm
Neotokyo - (4/5) - takes place in a fictionalized Tokyo approximately 25 years in the future. Mankind has begun to fuse with technology. Guns loosely based on real life, has an anime feel to it. objective is to capture control points on the maps to win. http://www.neotokyohq.com/
Domain 2049 - (5/5) - based in the year 2049, after a war, a "big brother" type government has control. Either fight as rebels, or USE the government agents. You must complete various objectives to win. http://www.domain2049.com/
UT2004 troopers - (3/5) - based on the star wars series, you play as storm troopers or rebels in team deathmatch style maps. http://www.ut2004troopers.com
AirBuccaneers - (4/5) - Tactical hot air balloon game. Basicly you have several weapons from rockets to a cannon and you battle it out from hot air balloons. Very interesting mod, although only fun when you have a good team. http://ludocraft.oulu.fi/airbuccaneers/
Alantis - (3/5) - Team oriented capture the flag style game, aliens vs humans story, basic but fun. http://www.atlantis.jolt.co.uk/
Unwheel - (3/5) - Racing game with loads of gamemodes, capture the flag to typical racing, outlandish cars as well. http://unwheel.beyondunreal.com/
Alien Swarm - (5/5) - Overhead view tactical squad-based shooter game, kinda reminds me of starcraft. It is a well made mod, and a interesting change. http://www.blackcatgames.com/swarm/
Jailbreak - (4/5) - Classic jailbreak, frag other player to put them in jail, while tryign to release your own team. http://www.planetjailbreak.com/
Duffers Golf - (2/5) - not much to say about it, it is a game of golf. http://duffers.beyondunreal.com/
Jungle Warfare - (2/5) - Classic terrorism game, maps and gameplay are lacking. http://www.junglewarfare.jolt.co.uk/
Frag Ops - (3/5) - Another classic CS wanna be, nothing new. http://www.frag-ops.com/
These are only the mods i have played so far, feel free to add your own opinions of the mods and other mods i missed.
