I loved the Pokémon Games when I was young and still consider it very much fun to play'em. Here I listed all the different generations of games because there has been a great amount of change. In my opinion the games until the 3rd generation Pokemon were the best. After that it got a bit boring and the Pokemon became uglier and uglier. (Diamant/Pearl/Platinum) The fifth generation doesn't neccessarily look better but with it came some fresh ideas.
Well, decide for yourself and enjoy the little nostalgia trip. ♥