Originally Posted by Fat EvilMario
The three Monkeys basically make the game-easy mode in the beginning.
I've had good luck with Munna (and evolution). It's an incredibly bulky Pokemon with good attack, although you'll have to resort to TMs (which are now unlimited) to go beyond Mono-Psychic. It receives multiple sleep inducing moves (Yawn, Hypnosis), and instant recovery (Moon Light). You can evolve it with Moon Stone at any time.
Evil Mario says it all. With the right typings, I've been able to plow through the game so far with just my grass monkey, and pokabu's evolution. Im sure I'll hit troubles along the way, but these two alone have either solo'ed or just dominated so far.
I also agree that Munna isn't bad compared to the other starting out pokes. That rat terrier aien't bad either.