I've just been wondering, because my mind has been wondering towards using a similar style for a game idea I have, whether or not there were really any other notable games that used the same perspective as the original GTA?
The strange mix of a 3D environment and what appear to be textured quads from an ordinary top-down perspective. I can't think of any myself, and I suspect there wouldn't likely be many examples given the very specific timeline where such a style would make sense; that being pretty much exactly around the time of the 5th console generation when the 3D would be practical enough for the buildings etc. but not quite for everything else. I would also assume that rather than go for such a strange combination (that happened to fit the gameplay of GTA very well), developers would have been more likely to choose full 2D or full 3D and design the game around that decision.
I was specifically thinking about making a game with a kind of 3/4 overhead perspective (e.g. The Chaos Engine, i.e. you can see the front and back of the characters), but decided the work of doing 8 different images for every angle of every frame was too much for my art abilities and would bog the whole development down anyway. I wanted the extra clothing detail of that perspective but thought I might get away with it anyway, except that seeing buildings only from the top would be kind of jarring if you wanted to create any sense of place, so I remembered the 3D perspective in GTA...