Like I said, you might not like this list. Overlooked in its time due to overshadowing by Mega Man X and for having been released last in the original NES series, Mega Man 6 is unfairly remissed. 6 is an excellent response to the common criticisms surrounding post-Mega Man 2 titles. Specifically, some felt that the gameplay had grown stale. Without stepping outside the basic formula (8 bosses + possible decoy boss levels + Wily levels = NEW MEGA MAN!), the title saw notable improvements.
The first was the implementation of "Rush adapters." Instead of using your robotic canine friend to spring to high ledges or cruise through the sky, Rush would transform into suits worn by Mega Man. The Jet adapter allowed Mega Man brief but infinitely rechargeable flight, and the Power adapter offered ... well, power. Both of these additions provided just enough freshness to the series without feeling cheap or tacked-on. This was particularly evident via the hidden passages that could be discovered by destroying walls with the Power suit. Although hidden passages were present in previous Mega Man games, 6 offered multiple stage routes including alternate boss locations. The Energy Balancer was an ingenious addition, as it allowed weapons to be recharged equally without having to equip them. Additionally, the final boss levels present some of the finest challenges found in any Mega Man or Mega Man X title.
Don't let common assumptions tell you differently; Mega Man 6 is a quality effort and a highlight for the series.
