Favourite Gen V Pokemon: Probs Chandelure. It looks amazing, has great stats, awesome typing. It's just an awesome critter any which way you look at it.
Least favourite Gen V Pokemon: Druddigon. It's just... there. Under normal circumstances, it would be awesome, but it really isn't. It looks fugly, is ridiculously slow, and just isn't good to use. For a Dragon Pokemon, it really is quite pathetic.