Garchomp is just stupid. Never liked it. Landshark thing... just looks stupid.
I don't like most dark types, because there aren't that many dark type moves that do a decent amount of damage or have an effect that I can find useful in a battle, however I do like Zoroark, Zorua, and Darkrai, but I couldn't care less for the rest.
Which Pokemon do you dislike the most? Why? Is it their available moves or stats? Perhaps they've really slow? Or just a type you don't like? Or perhaps they're just downright ugly?
Personally, I've always had a problem Magikarp - it doesn't do much for me with its moveset until evolved and I don't have the patience for that!
Snorlax. Don't get me wrong, I love the design of Snorlax. I also like having him on my team. The problem is fighting against him. Nothing does damage against him. He usually has the move Rest as well. Even when (after about 10 turns) you've done a decent amount of damage to him, he can completely re-heal himself.:facepalm: Unless you have a strong, Fighting-type Pokemon, it takes a really long time to take him down. Other than that, I like Snorlax. I suppose I like all the Pokemon in that respect.