Perikles - 1,126,010 - 2-4
Video
Japan conversion
Perikles - 2,046,820 - 3-2
Video
Fairly surprised I made it through the 2-3 boss in the Japanese version, he has an absurd amount of health and his patterns are usually not avoidable at all. He takes out your companions/wings in no time at all, crippling your offense, and once you're in your humanoid form you're dead anyway. 2-4 boss seems to be even worse.
He's pretty demanding in the US version, too, but at least the game is feasible until you hit loop 3 and its silly bosses. I find the 2-3 boss here to be fairly easy by comparison. It might be worth it to get hit in the final stage, you can rack up a lot of points when your animal buddies merely touch the stretching barriers, but that's obviously risky. Also nice checkpoint milking, Mero, took me quite a while to beat that score. 
