Inception
Pretty good - and kept me entertained. Nolan still doesn't understand pacing - but he has some neat, if not terribly original, ideas, and there's no denying he's got some talent.
I liked it a lot better than Dark Knight - which I consider a boring and pretentious mess - and I think it's about as good as Prestige/Batman Begins.
Memento is much more of an idea, than an entertaining film - and I doubt Nolan came up with it himself. It certainly reminds me of a certain game, and I seem to recall the game reminding me of a certain book.
Insomnia = zzz.
I'll probably need to see it a few more times to be certain, but it seemed to be somewhat inconsistent - but that's to be expected, when dealing with stuff like dreams. I don't think the whole "dream flavor" came through like I think it could have, but I suppose that's kinda the point. But I can't say anymore without spoilers.
In any case, it inspired me to think - and very few movies do that, these days. So that's a major plus.
7.5/10
Oh - and just to add, as good as it was, it's nowhere near Matrix-level good.