Lol that is a nasty answer, but that's exactly what I was tempted to answer. Chop Chop Tennis is fun but well it's an arcade game focusing on simplicity and immediate fun. The double it includes has more depth but this mode doesn't offer more than simple match. But as it is it's not really a Tennis game. But all I tried on iPad didn't caught me, they couldn't bring back the fun like I had with Jimmy Connors Tennis and few other I can't remember.
I read reviews yet can't find out what's THE tennis game to get..
I've tried almost all tennis games, and I think the best one is Real Tennis 2010. It's the closest we have to the awesome Virtua Tennis on Dreamcast, and the gameplay is intuitive. Touchsports Tennis is very flashy, but gameplay was quite poor for me, as it tries to be "touch where you want to go, tilt to aim" but for me the Virtua Tennis style of play is far better. Ace Tennis 2009 online was fun for its 3G-capable multiplayer, but frequent lags as I played against UK or US players, from Hong Kong. But as with most iOS games, you might not have many online players left as there's too many games to play!