I havent even PLAYED SH2, but there's something about Pyriamid Head, something sentimental, he's willing to actually torture/rape other monsters; it's like he's actually in the same situation you are, only he has a bigass knife.
The ELEPHANTS? I though they were tough but they deserved to be #7, not #1! Maybe I just a Megaman master, but I thought that nunchuck bastard from Ninja Gaiden is hardest on the list.