The Backstreet Boys were sure as hell influential for all the music that dominated radio for quite a few years, but that doesn't mean it was innovative.

In the strict sense of the word which Magixion introduced to this thread, influence, or impact thereafter, has nothing to do with innovation, although I'm sure most of us consider it an important aspect in our own personal meaning of the word.
This still comes off like you're confusing innovation for originality. Innovation is more like bringing something to the table that is a new take on an idea brought about through thinking, experimentation and growth, rather than something entirely new altogether. It remains a fact that Halo 3 put a buttload of ideas together in one game in an extremely functional and easy to use way on a format that it has never been achieved at the scale Halo 3 does it at before. That, to me, is innovation.