Gen 2. Meganium is so bad that it outclasses entire generations on its own. Its level of uselessness has always been a gathering point for my disappointment over the years. Chikorita looks good because it gets Razor Leaf early, but then SURPRISE! Nothing. You could waste some TMs on it, I guess, but why do that? Why give it a good attack like Earthquake when you could get more use from a Quagsire? There is absolutely no merit in choosing Chikorita.