Mega Man: Maverick Hunter
I played it at work on my lunchbreak yesterday. It's brilliant. Aside from the obvious graphical and musical overhaul, which is glorious (except for Spark Mandrill's stage, my opinion), It's like playing an entirely new game. After the first level, you've got an actual boss fight, rather than getting the crap kicked out of you. They relocated all of the power suit upgrades as well. That kind of threw me off upon not getting my Power Slide in Chill Penguin's stage. From what I've read, Vile's version more than makes it worth the money as well. I require it.