the COD4 / COD5 engine is nice but hardly the best out there , Raven Shield back with the Unreal 2 engine had similarly advanced bullet penetration . the COD engine's maps are rather small ,and the vehicle implementation is nothing spectacular.
I'd say the Unreal 3 engine is probably the best all round , great features + good performance , easy for programmers to use.
The Crysis and Dunia engines would come in next . GTA4's engine deserves a mention as well.
