The Evolution Man: Or, How I Ate my Father by Roy Lewis is one book that, after I finished it, caused an urge to go out into the streets and give copies to strangers. It's that funny. Or, at least I thought it was that funny. It's about a family of proto-humans at the point when fire has first been discovered. What makes this book hilarious is that the characters, despite their status as neanderthals, talk with plummy, upper-class British vocabulary and phrasing. It's as if PG Wodehouse had written a novel set in prehistoric times.
I can't remember much about what actually happens in this novel, except for an amusing caper when they kidnap some girls from a neighboring tribe--one of them is named "Prunella." The title gives the ending away anyway. This is the sort of book you shouldn't read in public because if you do, you will laugh out loud and make an ass of yourself.