To me, the spin-offs tend to be more fun than the original games, just because the original games tend to be a bit grinding in terms of progress. I've been playing a hack of XD: Gale of Darkness, and I have to say I'd most like to see a sequel or even a remake of those games (with updated mechanics). The second one for me is the Mystery Dungeons. Probably of all of the Pokemon games I played, Explorers of Sky is the one I would say I enjoyed the most of the Pokemon games. I've missed out on the latest games since I have no means to play 3DS games. Third is probably Trading Card Game. While I have played PTCGO, the game lost some value for me when the daily challenges involved having to play against human opponents. A very close fourth is Conquest, hoping there will eventually be another one with more Pokemon. I love strategy games and Conquest did that very well for me, just was a little disappointed in the variety of Pokemon chosen, and having to do each of the stories, some of them probably entire Pokemon campaigns in themselves, made me lose interest in fully finishing the games.