I just finished Puzzle Agent, and I have to say I had a great time with it. It's a blatant and unashamed Professor Layton clone, but it's a damn good Professor Layton clone. The hand drawn art style is very pleasing to the eye, the puzzles are interesting and engaging (if a little on the easy side) and it actually solves the age old point-and-click problem of having to pixel hunt for everything. It's a little on the short side, but that's to be expected from a $10 indie. All in all, I'd highly recommend it.
My favourite part of all has to be the fact that my favourite DS series of games is becoming popular enough for other developers to start making clones. It is a damn good formula, after all.