StarTris
There are lots of tetris style games or tetris remakes but this one is really cute. Graphics are nice, and gameplay is right on, the music and the background is kinda relaxing. Use LEFT and RIGHT ARROW KEYS to move the falling piece. Press UP ARROW KEY to rotate it and press DOWN ARROW KEY to move it down. Hit the SPACEBAR for quick drop. Every tetris fan should give this a quick try out. Have fun!