Max Sheik- ftilt and uair and up-b ridiculousness
3.5 ZSS- same improved recovery options, but before the 3.Q nerfs to superstrong fsmash and superfast dash and dsmash attacks
Others (All-Time Brokenness):
1.6 Wolf
2.x.6 Game & Watch, Olimar, Squirtle, Toon Link's Arrows
Max ROB and Lucario