Super Mario Bros.
Super Mario Bros. 1 is nothing like SMB 2. SMB 2 is nothing like SMB 3. Super Mario World is nothing like SMB 3. SM 64 is nothing like Yoshi's island. It's when we got the game Super Mario Sunshine that problems arose. Here, we got a game that many considered Super Mario 64.5. It was a very good game and taken by itself without consideration for the rest of the series, it's a GREAT game. Super Mario Galaxy 2 is a great game but it shares a little too much with the original Super Mario Galaxy.
Nintendo found a way to make every entry in the series feel unique. I bet you can find a ton of people that would say that one of these games:SMB1, 2, 3, World, Yoshi's Island, 64, or Galaxy-is the best game of the series. It's because each one seems to stand out from the rest in a major way. It would be a lot harder to find people that think the "me too" mario games are the best of the series.
Chris Rock said about relationships: "You gotta find a way to keep it new. If it ain't new, it's through." It applies to video game series, too.
