My ideal classic would be similar to Elder Scrolls IV: Oblivion, which was an RPG game from 06 on xbox and computer. It's a massive game, with about a hundred quests, a hundred different locations to find/explore, leveling, abilities, guilds, houses to buy, etc. The only difference is that it would have to be switched from single player to MMORPG.
Basically it's a nerd's heaven. Here's the link to the game's wiki page:
http://en.wikipedia.org/wiki/The_Elder_Scrolls_4