All of eevee's evolutions are good. I never used a single one of them except for in pokemon conquest. The new ice one, glaceon, is probably the best (on paper he has the highest spc. atk). He is pretty boss.
and I only just now tried to build my team with only high speed pokemon, not including Sunflora. My crobat has 163 speed at level 49, and that fat fucking lapras made him his bitch.
Glaceon or Vaporeon is the best in my opinion. Vaporeon takes hits all day long, but when Hail is up Glaceon is pretty much impossible to beat..
my level 32 feraligatr took out all 5 of Brock's 50+ rock/ground/kabutops pokemon. I literally used him as an HM slave but he leveled up to 30 eventually, evolved, and is now a beast. Kind of suprised. he only knows cut/strength/surf/waterfall