Crawdaunt, Cradily and Raticate. All 3 of these Pokemon are really great (though Crawdaunt does have big initial Speed issues).
If I had to guess, Super Fang, followed by a STAB Guts-boosted Quick Attack, or Guts-boosted Sucker Punch might make a dent in anything that doesn't resist it, and is a halfway decent wallbreaker strategy. Though honestly Crobat does the job better at wallbreaking, imo.... Care to actually justify those, ESPECIALLY Raticate?
Hey! You all forgot about Claydol!
nothing is nearly as underrated as zapdos. the subroost set just doesn't fucking die and will toxic stall you to hell and back. sdef sets are a pain too.
WHY DOES NO ONE LOVE BUTTERFREE ITS AMAZINGLY SPECTACULAR OMG ;-; X[ xP!!
Being SR weak and being walled by Heatran don't exactly do it any favors.
Anyways a really underrated mon imo is Jumpluff. I saw bubbly post an RMT with it, and it is the most annoying piece of shit I have ever used, it's incredibly effective. Once you kill the opposing grass type you can just abuse that blazing speed and go to work (think of a really really fast Breloom).
Swords Dance Empoleon
Raikou
Zapdos
I've got to say that Choice Scarf Scizor is one of the most underatted sets i've ever used. So many people just blindly assume that Scizor is Choice Band and switch in something like Starmie or Celebi to KO, only to be outsped and U-Turned. It's also absolutley hilarious to switch in on a Magnezone and outspeed it and KO with Superpower.