Lol. I had a conniption fit when I saw nightmare in Other M. I kept thinking to myself as I was running though the gravity stage "He's gonna come. He's gonna come." And when he did come, I literally paused the TV, walked up to it and yelled "**** you Team Ninja!" into the screen. Then I kicked his ass and it was all better.
Hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm. . . Can't really think of anything >_< Most boss fights I like in games are never the final bosses. Have to say Dark Samus/Corrupted AU from Metroid Prime 3. Constant phazon mode without being 'rejected' or losing health when using anything along with good graphics made the fight fairly fun. Same can be said about Genesis in FF VII:CC. At one point I thought I would wipe there so I was like "oh come on this is not even a hard fight, there is no way I'm going down here!". But I did like the Sepphiroth fight alot more tbh.
Well, there are a lot to choose from... well I chose: Vaati from TLOZ: the minish cap, Nebula Grey from Megaman Battle Network 5, and Marx from Kirby Super Star Ultra... and the I don't know what Emperor of Metroid Prime Echoes (forgot his name lol)