It is really nice to be able to get to know a city particularly well. If you live in the UK then there are certain cities around Europe that are very easy to get to. Places like Paris, Barcelona, Berlin, Amsterdam and other famous cities are easily reached via inexpensive airlines.
What this actually means is that you can go back time and time again. It might seem odd that you should visit one city over and over again when you have not seen some of the other cities around the world, but it is difficult to get a full appreciation for what a city has to offer unless you get all the touristy things out of the way first.
Then you can focus on really soaking up the vibe of the place and getting to grips with its less obvious charms.