Novel or memoir

I'd say novel. There's lots of novels out there that are very autobiographical. 'Portrait of the Artist as a Young Man' is one of my absolute faves.
Cool thing about writing a novel is that you can choose to lie as much as you want. Real life is so boring that I think you have to lie, unless you've had a fascinating life.
I saw Michael Chabon do a prepared talk in Denver, and told the story of how his first novel, 'The Mysteries of Pittsburgh' was written. He got about 125 pages in, and showed it to one of his professors at the time. It was autobiographical, and the professor told him it was boring, because real life was boring. There was a line MC used to convey how fat his father was, something like 'He settled his gangster bulk into the chair' (I'm paraphrasing, of course). The professor asked specifically about that line, saying "Is your father a gangster?" MC responded "No, I was just trying to say he was fat" and the prof said "Oh. Too bad. That was interesting." So MC started over and made the father in the novel a gangster.
I think I made a point...I hope I did.

If you write a memoir, everything has to be factual. If you have to make anything up, it would be a novel. I guess Goatpiper's point is that as soon as Chabon made the father a gangster, it's no longer a memoir.