I think the first 8 issues of Mega Man are pretty good. Proto Type and 2/3 of the finale (Rock and Blues' final issues) were the high point.
I also really liked Angelo DeCesare's Sonic, Dan Slott and Danny Fingeroth's short lived work, a few Mike Gallagher stories, a couple Bollers stories, and a good 20ish Ian stories. Sonic Boom's first four issues were great too.
If we're talking outside the Sonic sphere of influence Dan DeCarlo is a fucking legend and an artist I greatly admire, and some of IDW's weirder Transformers and GI Joe stuff is great, pic related.