That Wily theme from Mega Man 5 you posted is from the same album as the other three songs. xP For Mega Man's 20th anniversary they released two albums, one of techno remixes from Mega Man 1-6, and one of rock remixes. They're pretty great, if you haven't figured it out from the songs posted in this thread. :P

I Can't Beat Air Man is awesome. xP It's not an official Mega Man song, but it's great anyway. :P I've had the mp3 forever.