Flower, Okami, SotC, all the usual suspects. However, purely speaking in terms of art style, I also want to throw Love [http://www.quelsolaar.com/love/] into the mix. I actually haven't played it, so I can't really comment on the gameplay or story (if one actually exists in the context of the game), but if the screenshots are enough to go by, it's certainly worth my undivided attention at some point in the near future.