A few more.
N's Zorua for Mid. Very strong, good moveset (with TMs at least), but also extremely frail. He drops quickly even to neutral attacks.
Magnemite for Magnemite tier :)
Route 4 Minccino for High. Skill Link is phenomenal with his moveset, especially his evolved form (after Heart Scales that is).
Growlithe for Low. Would be High to Top if I didn't have to wait with evolving pretty much until level 45.. that's way too long.
Volcarona for Low. While it's superb at higher levels, it's simply not a good enough reason to drag her with you for the rest of the game...
Oshawott for Top, because he's a perfect HM slave~! :D
Swablu low. You get it rather late (right before 7th gym?). Boosted with DDs it's pretty good, but the problem is that it relies on those DDs nearly as much as Mandibuzz relies on Nasty Plot. I dragged it with me since that was my only source of Earthquake (did not manage to OHKO Darmanitan 4 levels lower even at +1 though...), but it did not see much action.
I think that's everything I tested so far.