Annoying Pokemon:
Magikarp: I hate it how there is always that irritating trainer in the game who has six of them!
Zubat: I hate it when they manage to confuse me or poison my pokemon when I'm trying to train!
Bidoof: It's so annoying. Just looking at it makes me irritated. D:
Bronzor: I hate this pokemon. It has like, no weaknesses, extremely high defenses, and knows confuse ray. Do I need to explain this one? x_x
Graveler: I hate the Graveler that are always on Victory Road and will use Explosion 95% of the time if you don't knock them out on the first turn! They're just horrible.
Useless Pokemon:
Jynx: She has horrible stats and can't learn many moves. I don't understand why she didn't get an evolution like Tangela, Magmar and Electabuzz!
Volbeat/Illumise: What is with all of these useless pokemon that don't evolve? They aren't good for anything, have horrible stats, and are begging for evolutions! It irritates me how these pokemon are made when they are completely useless.
Wigglytuff: I love the Jigglypuff evolutionary line, but Wigglytuff is just useless in the video games. Besides its high HP, it is completely outclassed by Clefable. : /
Luvdisc: Just horrible.
And pretty much any pokemon that has horrible stats, is fully evolved (or doesn't evolve), and is not good for anything annoys me. >_< Why are these pokemon created when they aren't good for anything? In my opinion, every single pokemon that is fully evolved should be useful in some way, and not just be 'fillers' in the pokedex. : /