Final Fantasy - One of the few series I very actively follow and try to keep on track of. Mainly, I play them for the story. Although the battle system in quite a few of them is quite fun.
Kingdom Hearts - I like it even though the plot has gotten really confusing lately. I'm kind of out of date on this one. The most recent game I have is Days. Still, the gameplay is probably my favourite of any series. So fun.
Pokémon - I also actively follow this one and probably the only one I'm up-to-date on. I like it mostly because of the monster designs.
Mario - I'm really outdated on this one. I've only really played the old SNES releases. But I like them even though I find them difficult.
Yeah, that's it. I'm not really into a lot of stuff. Kind of picky.