While there is a final boss in the games, Shin Megami Tensei 1 had this amusing thing where your final boss is determined by your alignment. What makes it amusing is that depending on your alignment, you could actually recruit the final boss of your own alignment and use them to beat up the opposing alignment boss.

Also DQVI has an optional boss you can fight who is way more powerful than the final boss. Beating him though has him destroy the final boss for you.