Previous games by other students that seemed to make good projects

• Bagels (note that you really want to do decent AI on this one, it's too simple a project without it)
• Battleship
• Boggle (checking if words are correct and AI is pretty hard, though)
• Chinese Checkers
• Clue (this was really complex)
• Connect Four
• Dots and Boxes
• Gin
• Go Fish
• Mancala
• Mastermind
• Othello
• Scrabble
• Set
• Parcheesi
• Wordsters
• Yacht / Yahtzee
• 3D Tic-Tac-Toe

Frequent misdirections (projects students seem to want to try that don't work out so well)

• Poker: the AI is really hard.
• Blackjack: the AI on this is really dull; you just implement a set of rules you can look up anywhere. I'd rather you do something that you need to think harder about.
• Bowling / Football / other sports simulations: These usually turn out really bizarre.
• Some kind of adventure / role playing game: this nearly always devolves into a massive set of nested if statements that don't really give you the opportunity to think about more interesting algorithms. This can be done right, but it's easy to miss the mark.
• Risk: getting the map is pretty hard.

Resources

Students who implement word-based games often ask me how to find a good dictionary of words to use. You'll find a fabulous word list on any of the department Macs in the directory /usr/share/dict, under the filename web2. This file is completely free and in the public domain (see the README in the same directory).