Fallout 3 allows you to basically become an ethnic cleanser, removing everyone with major mutations from the gene pool.
New Vegas Allows you to manipulate a mass conflict in a region either as the saviour of the mysogynist, cruel leader Caesar or the independant path.
Overlord has it as well, but more cartoonishly.
It's hard to think of a villain playing game where you truly become the villain. Villains tend to be proactive whilst the heroes/antiheroes are reactive. Not enough games with the ability to scheme, plot and produce a cunning plan to take ruin the good guys day.
New Vegas Allows you to manipulate a mass conflict in a region either as the saviour of the mysogynist, cruel leader Caesar or the independant path.
Overlord has it as well, but more cartoonishly.
It's hard to think of a villain playing game where you truly become the villain. Villains tend to be proactive whilst the heroes/antiheroes are reactive. Not enough games with the ability to scheme, plot and produce a cunning plan to take ruin the good guys day.