For enemies, depending on the character I'm playing, Surveyors annoy the hell out of me. They're fun to melee though, and it's a lot easier than you'd think. --- "You're breaking the game, dude!" - Borderlands 2's 'Gaige', on getting too many Anarchy stacks
Rabid Stalkers or Skags. Buzzards piss me off to no end as well. They're just so annoying to try to hit. --- http://www.last.fm/user/jebraymer Istanbul was Constantinople, now it's Istanbul not Constantinople.
Rabid Skags (good Exp though)... have yet to meet a Rabid Stalker but I expect they are just as bad.
Cursed Pirates on the DLC. I was in Co-op last night and they proved to be a total pain. I was a Lv 25 Gunzerker and the other player was a Lv 25 Assassin. Best results seemed to be with my (amazingly Lv 7) Wild Kerblaster.
Tinkles (from the DLC) on TVHM proved to be something of a pain and I eventually resorted to using the Skiff weapons.
And finally... those seriously strong Armoured Maniacs. --- PSN & Gamertag - RogsR34UK
Probably Rabid Stalkers except for when playing as Axton. Sabre Turret >>>>> Rabid Stalkers
I'd say Goliath Blasters are right up there with the Rabid Stalkers though. If you don't know your dealing with a Blaster when he shows up or kill him ASAP you pretty much are guaranteed to get downed(without using Sham). --- Foolish mortals and your petty squabbles Giga-Graviton > Zanmato
Rabid Stalkers/Skags annoy me the most. Anything flying DT/sentry turret(s) seem to be able to take out semi easily. --- GT: Boomer and Tank Pretty darn confident..... I don't want to have to wait till the Microendony XBOXS 4ii comes out another 15 years later....