- U.E.M 7
- UBerserker 2
- UbH-IceIst 5
- UBX Master 3
- UEd2 2
- UEM 13
- UFO 2
- uG-x`[ToM] 3
- UK-Scorpion 2
- Ulo & Einheit 2
- ULT Basement 2
- UltraSonic 3
- Ulysses_30 4
- Un1ucky 2
- Uncle_Bob 25
- Uncledumpy 19
- Uncommon 8
- UnconnecteD 2
- Underscore 5
- Undertaker 6
- UndrSiege 2
- UnFuKWitAbLE 10
- UnholyCreator 2
- Union 7
- United Scriptors 3
- United Scriptors : »SZO«Zeß 2
- United Scriptors: {NYA}Thainnin 2
- UnitedSniperMappers 2
- Unknown (original), EvilGrins (edited) 2
- UNKNOWN! REMIXED BY {DMF}SAVAGE 2
- Unknown, CTFM Conversion by "Karlos" 2
- Unknown, edited by Eric "DarMonkey" Olson 4
- Unknown/Fixes by Barbie 5
- Unknown/Modded by Barbie 2
- UnLeaded 7
- Unofficial 2
- UnPfhorgiven 4
- UnrealGGecko 7
- unrealKillers.com 2
- UNREALLOCO 7
- Unseen[WOLFIN] 2
- UnShame 7
- unXceptable 4
- UN||XpanD 7
- ur^Worlock 2
- Uri19 4
- urPackage 4
- UsAaR33 6
- Usama 4
- UT2003>UT Conversion by Howard_Stern 2
- UT2k4:Nagashi - UT99:Ghandi 2
- UTCP Maddmapper: Dave {Maddog} Mortensen 3
- utdemon 7
- UTGhost / Ryu_Senshi 2
- utinstafreak 2
- ù)v(indz-$l@y3r 2
- ÜberByte 2