The only problem with some of these is that it's hard to have an exact same run every time which could mess with results
Gotta run them a couple of times and get an average.
here is a list of all games with built in benchmarks
Games with built-in benchmarks
DroneZmark ( Built-in Benchmark )
FarCry ( 2 pre-recorded Timedemos, record/playback timedemo available )
Crysis ( 1 pre-recorded GPU Timedemos, 2 pre-recorded CPU Timedemos, record/playback timedemo available )
Devil May Cry 4 ( Built-in Benchmark )
Call Of Juarez ( Built-in Benchmark )
Doom III ( pre-recorded timedemo, record/playback timedemo available )
Quake IV ( record/playback timedemo available ) [ I think there's also a dedicated benchmarking application from HardwareOC available ]
Prey ( timedemo recording and playback capabilities )
S.T.A.L.K.E.R. : Shadow Of Chernobyl ( timedemo recording and playback capabilities )
Enemy Territory: Quake Wars ( record/playback timedemo available )
Call Of Duty ( record/playback timedemo available ) [ or use BenchEmAll's timedemos and automated features ]
Call Of Duty 2 ( record/playback timedemo available )
Call Of Duty 4 ( record/playback timedemo available )
Tomb Raider: Angel Of Darkness ( BenchEmAll )
The Chronicles Of Riddick: Escape From Butcher Bay ( dedicated benchmark application available, goes by the game's name followed by the word benchmark )
F.E.A.R. ( Built-in Benchmark )
Unreal Tournament ( record/playback timedemo )
Unreal Tournament 2003 ( record/playback timedemo & BenchEmAll )
Unreal Tournament 2004 ( record/playback timedemo & BenchEmAll )
Unreal Tournament 3 ( record/playback timedemo & Dedicated Benchmarking Utility )
Counter-Striker: Source ( Built-In BenchMark )
Half-Life 2: Lost Coast ( Built-In Benchmark )
Lost Planet ( Built-In Benchmark )
World In Conflict ( Built-In Benchmark )
Company Of Heroes ( & Opposing Fronts ) [ Built-in Benchmark ]
Supreme Commander ( Built-In Benchmark ) * not 100% sure, my memory....woes
x2: The Threat [ Built-in Benchmark ]
x3: Reunion ( Built-In Benchmark )
Comanche 4 ( Built-In Benchmark )
Serious Sam II ( record/playback timedemo )
PT Boats: Knights Of The Sea ( Built-in Benchmark )
BattleField 2 ( record/playback timedemo & HardwareOC benchmarking utility )
BattleField 2142 ( record/playback timedemo & HardwareOC benchmarking utility )
Half-Life 2 ( Built-In Benchmark & Benchmarking Scripts available )
Painkiller ( BenchEmAll )
Halo: Combat Evolved ( BenchEmAll )
Splinter Cell ( BenchEmAll )
Return To Castle Wolfenstein ( record/playback timedemo & BenchEmAll )
Unreal II: The Awakening ( BenchEmAll )
Quake III Arena ( BenchEmAll )
(thanks ashen)