Smaug the Impenetrable as a very masochistic commander. The game plan is to get him in the field as soon as possible, then causing as much non-combat damage to him to generate a butt load of treasure. Working toward pay offs of either treasure enter triggers (Mirkwood Bats, Reckless Fireweaver), Big X spells that can take out your opponents (Comet Storm, Fireball), or alternate win conditions (Hellkite Tyrant, Revel in Riches). Pariah Shield creates extra value, turning any damage you take into even more treasures, and Pain for Fall turns all that self damage to potential player removal. There's also a some synergy with other indestructible creatures that also benefit in getting hurt, since you have a plethora of ways to deal damage to your own creatures, which can equal to player removal.