pretty much what this topic is about is, what pokemon can pretty much carry you through the whole game?
and this is excluding only using one pokemon. we are assuming full teams being used evenly here.
to me, gen 1 is nidoran for being early, and able to beat brock, surge, eirka(with ice beam), blaine, koga, and giovanni, all without being way over levelled, can be done without x items, and without horndrill.
for gen 2, obviously i think its geodude. gets rock throw by lvl 11, and can solo the first gym as low as lvl 6. then gets magnitude at a low lvl too. he's good for falkner, bugsy, can beat whitney, can beat chuck, jasmine, and price. not gonna count the kanto gyms.
the other gens, i havent played recently enough to know...
"when I'm in the process of doing something, I do it not because I think it's worth doing, but because I'm trying to MAKE it worth doing."