Very few games are as iconic as Grand Theft Auto III, and it's recent release to iOS devices does not tarnish its reputation whatsoever.
I played the game on an iPad 1 this morning. I found the controls far more intuitive than I could have hoped for. The game is still a full experience, and even after 10 years of sequels it still doesn't fail to be a great game.
The game is out now on iOS for $5. It runs on iPhones, iPod Touches and iPads that run iOS 4.03 or later.