I would be sakuya beause she's awesome.
Assuming I'm not sakuya, I would hang out with reimu because she won't freak out over anything, Patchouli because she's smart, Marisa because she's clever, and the band because I like music.
And others but I don't know them off the top of my head.
Wait... the "Art of Assembly"? Are you insane? You read all of it?
That's a multi-course college-level textbook in assembly programming. I doubt that anyone, even the experienced hackers, would be able to comprehend all of it.
Some of the chapters actually aren't very important since they have nothing that's related to cavestory hacking.
EDIT: it's a good place to find some neat assembly tricks, but not intended to be read as a guidebook.