Big, bold numbers: this might be the best-looking watch face on the Pebble. The numbers slide into place when the time changes. Plus, date and day are tucked away on the bottom. This is the best use of Pebble display real estate on a watch face I've seen. (All Pebble apps were downloaded via Pebble's watch face directory and mypebblefaces.com.)
Someone actually made a Tetris clone for the Pebble, and it works pretty well. The right-side buttons move the blocks left and right, while the middle button rotates. A little hard to control on your wrist, but it's free and it reminds me of Nintendo's Game & Watch.