Currently (after format in mid-September)
*Ballistic Weapons v2.1 (including Bonus Pack 4) (pretty much frequently used since 2007, the year when I first have UT2004)
*WoRM 2k4 (to use my custom weapons and items)
*Vehicular Genocide/Homicide (Would have been more fun if bots on my team are not daft!)
*UTXMP, just to get GreatEmerald's U2 weapons working, although I do play this mod occasionally)
*U2 Weapons by GreatEmerald.
Mutators currently (after format in mid-September)
*Heavy Vehicles (sick of the Scorpion being kicked around?)
*Verbage (changes You killed Mr.Crow to other verbs like You fragged Mr.Crow or other verbs of your choice)
*Alternate HUD (I seem to like UT2003's hud better, although almost pretty large.)
*Tactical Shadows (from Fraghouse. opposite of bright skins)
*Pinata mutator (players drop everything when they die. Seems to be bugged on Ballistic Loadout, where only the certain group of weapons are dropped.)
*UT3-Style Slow Time Kills (game goes slo-mo for a certain time after killing someone, even yourself!)
*Ejection. (Players eject from destroyed vehicles--AS style, yet sometimes they die because the destroyed vehicles hit them or explodes near them.)
*Pretty much others I did not put up here. I could say Species Stats, yet it was with the game.
Before I formatted, I did have at least 18 GB total size in UT2004.