Trying to get as many war crimes committed as possible ahead of the midterms?

World of Warcraft, but predominantly as a persistent single-player world where you can invite players in (ala. Diablo 2).

I love the world building of Azeroth (even the bow out-dated, throw-away, pop-culture additions); just wish I could play and experience it all at my pace - family life currently precludes me from being able to invest sufficient time to play an MMO.