Before making my argument, I'd like to show you what most sports leagues do for their table points (as many as I know):
NFL/CFL: The old 2-1-0 (W-T-L). This system is the most common.
NHL: The 2-1-0 system, but with a bonus point for an OT loss and no ties.
NBA: Just wins.
MLB: Wins, unless percentage dictates otherwise. Playoff berths decided ultimately by committee.
AFL (Australia): 4-2-0. Same as the 2-1-0 system.
NRL (Australia): 2-1-0, with an overtime.
Soccer: 3-1-0. Bonus point for a win.
Rugby Union: Convoluted. 4-2-0, with an extra point for scoring 4 tries AND/OR losing by 7 points or less.
I believe that Rugby Union has the most complete system out there, but I don't like the 4-tries bonus all that much.
Look below for my new proposal.