Assuming you're neither really big/strong nor really small/short, then my two pesos' worth:
1. Either a 2000 CR250 or a KX250 that's in very good shape. Essentially equal bikes, plenty of power, good handling and suspension. Buy based on condition, accessories, etc. Do NOT get a CR w/ the aluminum frame from any of the years before '00!
2. CR500 if you like rocketships, have the strength and ability to hang onto one, want a low-maintenance bike and absolutely MUST have the holeshot.
