Minecraft wiki entry for Beating_a_challenge_map, associated text: Healing: Good to have on your hotbar, because it not only heals you, but if turned into a splash potion, it can also damage undead mobs, such as zombies.
Regeneration: Great for runthroughs or spawner rushes, as any damage you receive will be negated quickly while having the Regeneration effect.
Fire Resistance: Fire Resistance makes blazes and ghasts a lot easier to deal with.