Hmm... For me it's gonna have to be Deus Ex (Which I've played through six times), Diablo 2 (Also six times), or Freelancer (I lost count of how many times I've played through it).
Oh god the hours i put into pokemon red and blue.... 120 hours of blood, sweat and tears. Then my baby sister comes along, wants to try it, and saves over my account with a lvl 5 bulba.. The rage, people, the rage...Adventurer2626 said:Pick up RTS as a hobby. There's the Command & Conquer series (Red Alert series, Tiberian Sun series, Generals was ok), Starcraft 1&2, Stronghold 1&2 and Crusader, and the entire Total War series. I promise you, pick your favorite one or two and you will loose WEEKS of your life to playing time(potentially on par with Pokemon even, that evil, evil game). Especially if you find you like the Total War series. It has a campaign map where you manage your empire and direct your armies to attack and defend cities (which you manage, if you like). There are multiple factions to play and in many cases you can manipulate the files easily enough to play most if not all "unplayable factions." Then the battles themselves are in real-time or have auto-resolve if you don't feel like it or trust your general more than yourself (not usual). Or you can even make your own skirmish against the computer (with computer allies if you desire).
Have fun!