least favorite would have to be Torchic's entire evolution line.
I must agree with PersianTrainer, my favorite pokemon was Linoone.
my reasons are the followings:
1. The pickup ability (i love that ability in game for free items)
2. One of the few pokes that have the ability pick up after evolve. (from zigzagoon to linone)
3. He can learn a lot of HM, some of them even can learn the surf
4. He obtain the covet move, that move in emerald was so useful to me for obtain heart scales from ludovisk.
5. No matter what teams i choose when I play again emerald, in the adventure in game i always pick a zig zagon.