Unless you manage to rat an Steam account with any games in its invintory, it wont be worth much. It's rather hard to sell a hacked steam account considering you'll have no information to give with it (to secure the sale) nor to stop it being recovered, seeing that steam accounts are easily recovered.
On top of that, even if you hack somebody with games in their invintory, if they simply ticketed what happened/called (w/e) they could get the games back that you hacked from their invintory (if you happened to do so) and you could be traced/penalized for it.
overall... definitely runescape