Okay, I'm gonna do a quick summary of what I think are the good ones:
Know how to change a tire
Know how to undo a bra with 1 hand
Urinal ettiquette
Know some basic shop skills so you can build stuff
Know some basic home repair skills (drywall patching, changing a faucet, changing light switches)
Know how to build a fire (bonus points if you don't use any newspaper/starter/fluid... just wood and a match)
Know how to drive stick
Know how to jump start a car
Know how to grill/barbeque
Know how to perform oral on a lady

Know how to tie a tie
Know how to play poker
Some beer knowledge is probably a must too... either knowledge of your favourite beer, or how to open a bottle with something in arm's length... just one thing to do with beer.
Sports knowledge is a definite bonus. Not quite a necessity, but it's something most guys should know. There probably will be conversations in social settings where sports will come up and you'll probably want to get in on it to get noticed. Gotta know a little bit.
Oh, and another bonus is being able to kill your own food. Doesn't matter what it is, but if you can fish/hunt/whatever, kill your own food, clean it and cook it, then that's gotta count for something too.
I guess you could consider the last three things as substitutes in case you can't do something on the list.