I played pretty much every pokemon games ever, and I seriously don't mind the new Generations bringing a bunch of whacky new pokemons.
Not only do I agree with NekoNekoRex (Not the same damn things again and again), but it also messes up my type memorization. If we kept the same pokemons all the time, I'd just, y'know, use the same move over and over again on what I know will be murdered by said move. Now I can play the fun guessing game of what type my enemy is. It's silly, but it keeps me entertained when I stumble on random encounters.
Also Audinos are the greatest thing ever. When dead, obviously.