I've never played the new games, nor do I have a 3DS. I just have the old original DS that takes GameBoy games. I can't remember which games I've played exactly, but I've played quite a few. I prefer the older Pokemon in general and started... not losing interest, but not caring for the Pokemon once Generation 4, aka Sinnoh, came into the picture. Though, there are still Pokemon that I like in the newer regions.
I guess I could use the rest of this to talk about myself, but I'll put it in a hidebox, as some of it may not be what people agree with and I don't want to offend anyone.