Either Mario World or Mario U objectively speaking. Personally I haven't played Mario U so I have to say World for now. Hotel Mario is clearly a close third.
You should check out my YouTube channel, The Golden Bolt! I review all types of video games, both classic and modern, and I also give short flyover reviews of the free games each month on PlayStation Plus to tell you if they're worth downloading. After all, the games may be free, but your time is valuable!







