O2

O2 have dedicated salesmen, who are just a hassle and annoyance if you are only looking. You tell them you are only looking, and you tell them and you tell them but still they insist on showing you a variety of handsets, to which you may or may not have interest in even purchasing.
The problem is that you need to look around when you are thinking about a big long 18 month contract with a provider. Thing is O2 had the upper hand for a while because of the iphone but now everyone has it.
The stores people are really helpful when you do have a monthly contract here and need some help. I always go to the sauchiehall street store because they have always went out of their way just to make sure any problems are ironed out.