Arcade Dario Accornaro's TheZone is an excellent one-player asteroid game with a huge playing area and a spaceship which is always centered. Collect goodies and shoot at easily annoyed aliens.
Emphasis lies in collecting money to upgrade.
I recommend using the ship with the best shields and purchasing insurance wisely. John Stiles' Skittles looks a lot like Doctor Mario except that there are more colors and the dots only have to make contact, not necessarily in rows. Play versus the computer or in exciting two-player competition. Tetris Max is generally agreed to be the best implementation of tetris for Mac. There are many options, including two types of drop keys and customization of music and graphics.