The best types of potato to roast are those that are floury (rather than those with a waxier texture). The floury surface is what will help the potato go super crispy on the outside when roasted..
If you're in the UK the varieties to look for are Maris Piper, King Edward or Desiree. If you're in the US then go for Yukon Gold and in Australia look for Desiree, Dutch Cream or Coliban.