I really like Bisharp, Durant, and Mandibuzz, but you can't find them until so late that it's just not worth leaving an open spot in your party for so long, not to mention the crazily late levels they evolve at. Seriously, fifty-four!? Why would they even do that?
Route 103. Where Wally found his...Agreed Feebas, also dem Deinos and don't let me forget, those awful Ralts in Emerald. God where are those Ralts?!