There are a lot more possibilities, so let's try to organize some of them
But a properly built lifegain Commander deck is one of the most resilient and explosive archetypes in EDH because it treats life as a resource to be spent , not a number to be hoarded
Sarkhan Planeswalkers If you're playing dragons, the various versions of Sarkhan are basically made for you
Of these four, I think Library is probably the only serious candidate, but even that is pretty unlikely
Thanks to Proliferate, its a reasonable play it on turn one, and its also a great draw when Im mana-flooded
Keep in mind that damage will still be dealt normally though, even if a player doesnt gain life now