Online Gold Slam
Gold Slam is a 3d, third person tennis MMO. No special attacks or power-ups here. Gold Slam is very technical; all shots can be manually aimed and controlled. With realistic graphics and game play, Gold Slam is the most authentic tennis game in the free to play market. Play singles (1v1) or doubles (2v2) matches to earn GP and level up. Purchase new rackets and clothing to improve your stats and customize your appearance.
Official Site: http://goldslam.aeriagames.com/