Recently I got Bahamut in FFV. far from a challenge in FF but i died the first few times i went up there and didn't even bother my first playthrough.

Beating VII was a big deal for me. Really wanted to see how it all ends, same with the rest of the main series, but not nearly as much.

Beating VIII was also big because it was like 5th/6th attempt, the other times I either got stuck or said "screw it, this game is gay". My opinion is completely reversed now though.