You can't compare certain film genres, but when I left the cinema I realised the same thing : this could be the best film I ever saw ! Nolan is now untouchable for me !
Before I saw it I was a bit concerned about the dreaming, because too much freedom can ruin everything (anyone who can remember "The Cell", for me that's one of the worst films ever made), but he used it in such a way I wanted to see, it's really incredible. And that's only the script ! Yes finally a film where the script got the most attention, in many films the script is so bad it completely ruins a potential big hit (Centurion, just to name one).
And then it has the perfect dose of emo/romance, a great cast (yes even Ellen Page is doing a great job!), no real chicks (always the biggest candidate to ruin a film), a lot of action (but not overkill), perfect dose of fancy stuff (again, no overkill), and the whole film is really focused on the story, not confusing (might sound strange, but I think it couldn't be done better).
Anyone with a bit of imagination and intellect SHOULD see Inception, really, if one film is worth the money, it's this one, hell I will even go see it a second time ! Anyone who doesn't like it, is being an ass or just plain stupid