I'll just list a few B/W ones:
Palpitoad looks far better than the ugly as all get out Seismitoad. Pansear owns Simisear. Shelmet's one I thought would have an awesome ev, and then it becomes Accelgor. Eew. Hate the Swoobat design, so I'd have to say I prefer Woobat. I also actually prefer Herdier to Stoutland, though that might just be because Herdier looks an awful lot like my real dog.