the hl2 engine is great too, I had a chance to play the hl2 beta and even though I wasnt able to kill I had hours of fun just playing with the gravity gun
The Doom3 engine sucks... And don't disagree with me unless you know how engines work. Look at the architecture and instruction methods and you will see.
in farcry, it was amazing, when i walked from a small room out into a huge open area with a long bridge and view. That kind of work is why i think it is one of the best engines made yet.