Anything with Speed Boost looks good. Literally, anything. Trappers with at least reasonable movepools look better as well.
Most bugs look like they got better due to already having good movepools and abilities:
Volbeat looks much better, and can run an offensive Tail Glow set under this, in addition to his usual Prankster support sets, only now with much better bulk.
Venomoth gets Quiver Dance, Tinted Lens, and a huge movepool. Also has an enormous support movepool usable with Wonder Skin.
Any of the butterflies now with usable bulk to go along with their Sleep Powder/Compound Eyes
Crustle or Shuckle can run Sturdy, Weakness Policy, Shell smash
And finally, a Sticky web user who doesn't suck at that job, since they'll now all have better bulk.
A lot of things look like they'd be better at completely different jobs with a different stat distribution:
Azumarill: With Huge Power banned, can now run Sap Sipper and only has 2 weaknesses. (only one to a common attacking type). Good typing, and access to many support moves (Encore and Perish song come to mind, especially in combination with Whirlpool).
Empoleon: Good typing, Defiant, Swords Dance, good physical movepool including priority.
A lot of random things get moves they wouldn't have been able to use before/were outclassed at using due to stat distributions/poor stats in general, such as Belly Drum.
Ditto looks fun. Not just because of better HP, but also to see the kinds of movesets people come up with.