I would say this game is among the best Ratchet & Clank games available today, but not the best. It looks very pretty, and is quite fun, but the characters are a bit of a letdown, and the story isn't as well executed as I would have liked it to be. I think I would put it on equal grounds with the original game, but I think I would prefer R&C2 or Tools of Destruction.
I am very much looking forward to playing more games after this one. The story can only get better, and I am sure the characters will remain terrible, but I guess that is what we get with R&C games since the release of A4O.