Megaman 6 was not the best in the series, but it still is a classy game with some decent music, cool bosses, and an inexcusably weak cameo by Protoman.
More than anything else, this game was a setup for Megaman 7 for the SNES. It brought the NES series to a close remarkably well and still left us yearning for more. This game is like my little sister--stuck in middle school, but eagerly anticipating the next level up, high school. The graphics are about as advanced as the NES gets, it has a real plot... Ultimately, this is a worthy "conclusion" for a fantastic series.