Question: This question may be interpreted as "too localized", but it is not.

I'm interested in what you find to be the best sites for this type of operation, regardless of where they are located. For instance, I want to learn about how do these sites do the following:

* How do they work with geographic information?
* What search parameters do they use?
* Can you personalize your search? How?

and so on...

Answer: 
The ones I've had most sucess with is:

* [Rightmove](http://www.rightmove.co.uk/)
I like [Nestoria.co.uk](http://www.nestoria.co.uk) for its combination of list and map search. 

Moving around the map refreshes the search listings around the centered location.