There are hundreds of different card games.
Most of these variations are of Solitaire. Many magic types (and those that fancy themselves educated) often seek the deeper meanings of the elemental interplay of the turned and buried cards.
Poker, played with six cards to a hand, is the "man's" game. Holdout, studs, and draw version exist.
Pokia is a poker like game. Instead of betting money, points are awarded by how the play goes.
Folding first round, 0 pts
For each round of "betting" +1
Losing the hand -3 pts -1 per round of betting
The quality of the winning hand determines points awarded: 1 to 12 points.
The game ends at 60 pts, or whatever value was set before.
Hearts, Bridge/Whist, and Rook are common polite games, played by adults.
Pull out Hoyle's rules, and find hundreds of other games.
There are dozens of children's games as well. The Magic Guild occasionally gives decks out to children at schools and temple. They use them as a testing tool.