I love GTA3 but some of the mission later on become almost impossible with the virtual controls (mostly because of aiming), I'd recommend Chinatown Wars (although the controls can be frustrating on that as well)
Is much as I like GTA 3. Chinatown Wars is just incredible, one of the best games ever made on any platform. But with that being said, I haven't played it on IOS, my experience with it come from playing it on the DS. But the IOS version has better graphics.
with out GTA1 and GTA2 GTA3 wouldnt be around they were far more popular then you think and at the time you have to remember how many people were gaming in general compared to the time when GTA3 came out. gaming exploded into the mainstream making the numbers soar so yeah GTA3 was more popular cause it hit at the right time. doesnt change the fact that 1 and 2 are awesome.
and for IOS china town wars IMO is a much better bet.
ErrorSupply 3-D DS -OMG! It's the ultimate anti-pirate tech O:.