27. Metroid (NES)

A new legendary character was born, and I won't spoil it for you, but most know what I'm talking about probably.  In any case, I believe this was really the first side scroller where the adventure hero could manipulate a simple 2-button controller into so many moves.  It was definitely a fun feel, and incredibly challenging.  It was kind of like a maze within a story mode.  And it wasn't just a side scroller, for the most part it was, but you could also have times where you're going up or down.  The Metroid series would be around for a long time.