Recently I've been using this current moveset for my (4 HP/252 Sp.Atk/252 Spd) Blastoise:
Item: Choice Specs
Note: The two HMs are entirely for the overworld gameplay.
Blastoise can outspeed about half of his opponents I find, so the idea of Water Spout being in the moveset as a lead still sounds appealing to me. However, the Choice Specs isn't giving me the boost I was quite looking for. Choice Specs + Spout + Maxed Sp.Atk = OHKO most battles, but being locked into Water Spout sets me at a disadvantage due to the constant switching out, when the opponent outspeeds me or I'm against that evil Vaporeon that has Water Absorb.
So... any tips?
I'm open to anything really. I just like the idea of Water Spout.
:( Try Hidden Power Grass / Hidden Power Electric > Watefall? But that does mean you have to breed another. Otherwise the best choice is probably using a Life Orb.
Nevertheless, for future competitive-related questions (since Choice Specs/EVs fits more in competitive questions even if it's in-game as those who play in-game are less likely to know of that), use Competitive Team Questions. n_n