The ways of enjoyment:
1. Joy of playing
2. Joy of winning
3. The Social event of gathering to play
4. Joy by Tinkering
5. Joy of collecting
6. Joy of sharing
7. Joy of Learning
In detail...
Fun of Playing
For some people, the play of a game is its own reward. For many people, this is true of some, but not all, games.
Fun of Winning
For most of us, winning is, itself, fun. One experiences some joy at winning, especially in the face of adversity, be it a hard solitaire or a multi-player contest.
For a few, playing isn't fun, but winning is; playing is the cost for the chance at the fun of winning.
The Social Event
Some people's enjoyment is about or enhanced by the social event aspects of board and card games. The gathering is itself fun, even if the games themselves turn out not to be.
Conventions are an extreme example of this. My own local group of friends seldom gather without something hitting the table.
The Joy of Tinkering
For some people, house rules aren't for fixing things that didn't work, but a way of finding enjoyment all their own. By expanding, revising, "pimping," or strategizing, outside the playtimes, one can find enjoyment of a game.
Pimping a game means acquiring or making better looking components than the included ones... and it borders on...
While not properly "tinkering," strategizing falls into the same basic mode - deriving non-play enjoyment from spending time figuring out how the game works.
The Joy of Collecting
For some, enjoyment is in the having. Either by getting everything for one game, or having lots of games.
The Joy of Sharing
For some, the joy is in the sharing of the games. Either by teaching, by revieing, or by discussing with others.
In some ways, it's similar to the joy of the event; in others, it's different. As with collecting and tinkering, a lot of this is outside the actual realm of playing the game.
The Joy of Learning
For some, this is part of the joy of playing, or of sharing... for others, it's an enjoyment factor all its own.