I'd put (FPS, TPS titles are per post)
1) Crytek (I'm actually not sure its optimized as well as it could be, it's a hog but there's no denying what it can deliver when enough horsepower is put behind it)
2) Naughty Dog engine (my favorite console engine this gen. I love its capabilities and the way it more or less removes concept of levels delivering a seamless flow (apart from one or two big scene jumps) from one area to the next.
3) Killzone 2 engine (very impressive engine, the Crytek engine of consoles I guess.)
4) Source engine (actually my favorite in many ways but not quite as shiny now)
5) Unreal engine (a great engine, powering a lot of fantastic titles plus a favorite of mine since Unreal Tournament)
I'm very interested in ID Tech 5 and the engine underneath Alan Wake and Heavy Rain, but until they're released I don't think you can count them.
Gamebyro is also a good, robust engine and I liked it very much in Oblivion and Fallout 3. The Chrome engine is pretty good but still seems a little flaky here and there IMHO.
Try to be reasonable... its easier than you think...
