Well I obviously like the various Pokemon games.
In the Pearl version of that I had beaten the Elite 4 & Champion over 400 times.
I had somewhere around 400 hours in that game. Most of which was getting eggs/hatching eggs/leveling up Pokemon to evolve them (using EXP Share while one Pokemon trounced the E4/Champ was the best Exp gain in the game).
Of course back then there was no real help in getting the various Pokemon.
Now they have stuff like Egg Breeding Services, Cloning Services, and Special Pokmon services (leveling up, editing, etc).
Plus special sites you can get hard to find Pokemon (legends).
So with those services, what took me over 400 hours to complete only took a bit over 100. Yep that's right I yet again have every single Pokemon in existence in the PC storage system.
Of course this is in preparation for the upcoming Pokemon X/Y for the 3DS.
I also enjoyed Final Fantasy 9. It was cool having the "retro" look for the game. It was also a much more interesting & fun game than 8 (boy was that last area annoying on that).
Of course I have played pretty much all the Final Fantasy games (with the exception of 11 & 13). 12 was OK but seemed to be a bit too hard.
I also have played almost all the Zelda games. Though I missed Majora's Mask & Wind Waker due to no N64/Gamecube.
Not really sure which one I liked the most, but Phantom Hourglass was pretty fun.
That's 649 Pokemon by the way.