If I may put a gen 5 pokemon here, smugleaf 3.0.
Speed and thats it.
Sure, leech seed and all of that stuff, but Sceptile fufills it's role better.
For gens 1-4, Pikachu.
The mascot of the fucking franchise sux like hell unless it holds a light ball and even then is so easy to OHKO?
And it's evo is only usable in NU and UU?