The most impressive engine, in my eyes, are the ones that can have current gen console games run at 60 frames a second! To my knowledge few can do that. Game engines are common, and it would appear any development team can throw one together. And many do, and equally they boast about what it's capable of.
I hope come the next generation of consoles, when we're finally (hopefully) running all games at a decent framerate, with realistic shadows and lighting, etc, and discussion of game engines becomes as important and popular a subject as drivers discussing what oil they put in their cars! I'd hope the industry, and gamers move away from the (let's face it; dull) technical discussions and have more to talk about in terms of features, AI, story, characters, etc. The things that matter. Alternatively, maybe in future when we come out of effects heavy movies we'll ignore the story, characters, direction, etc and discuss how good the effects software is at Industrial Light and Magic, Weta Workshop, Sony's Imageworks or whoever!!