There are so many good golf games to play, most of which have rules that make betting easy, too.
One of the greatest golf games takes a lot of skill and guts, and it's called the Skins game.
The rules of a Skins Game
There are two ways to play a Skins Game: the traditional made-for-TV Skins game that is a match play-style format, as well a skins game based on scores during a tournament round.
Match Play Skins
In the match play format, you only need a minimum of two players, and each hole is scored like match play, with the winner on that hole being the player with the lowest score (with or without handicap). However, if there is any kind of tie for first place, then no one wins the hole (it's call One Tie, All Tie). Typically, the skin for that hole then carries over to the next hole, making it worth two skins. Ties continue to carry over until someone wins outright, collecting all outstanding skins.
In some formats, only players that tie on the previous hole are eligible for carry-overs. Sometimes that can create lots of mini-matches for carry-overs through the round. Also, there's been a version where a player essentially has to win two holes in a row to get skins, which is silly.
At the end, the player with the most skins wins and is typically paid a per-skin amount by the other players in the game in the amount of the difference of skins between them and their opponents' individual skin totals. Usually the amount per skin on each hole increases throughout the round to give all players a reason to continue trying hard until the end of the round. Sometimes, groups choose a set amount that goes to the winner from each player regardless of skins won, but that's lame.
In this form of the Skins game, there can be teams, and they can play as a single unit to determine which side wins a skin. That can be played in any format, including best ball and alternate shot.
Whole Round Skins
In this version of the Skins game, you don't know who wins until the round is finished. Players put money into a pot at the start of the round and play the whole round out. Every time a player has the lowest score for the round among the competitors, they earn a skin. At the end, the pot is divided up by the number of skins and money is doled out accordingly. Carry-overs apply in this format, and that can make for holes worth a tremendous amount to the competition.
This is a great format for games that span multiple groups because it encourages aggressive play and adds a little post-round drama.