I have never been on the London Eye, flebastian, but I would say that I had a great view of the city if I could see most or all of London from the top of the ride. "Over", "across", and "on" don't strike me as normal prepositions in that remark.
You are welcome. I don't know whether they express the idea differently, but I doubt that they do. I suspect that "a great view of the city" is a normal phrase in Great Britain just as it is in the United States.