If we stick to legitly gaming, FarCry2 will consume about 3 years of your life to get max online level, tied to a gold trophy. If we talk about raw skill, i felt real pain achieving platinum on Wipeout HD. But the winner is "Fight Night Round 4: Platinum Imposible", where need to find and defeat 3 unique belt owners around the world, wich no longer play holding them forever.
PS3TrophyIsGood cant resign trophy files, so u will never be able to sync them properly, thats why your psn rank doesnt grow, and ure risking your account to ban. Rebug firmware will give u real control over trophies:
http://rebug.me/