James B.

Well, if you go in store to buy a game or DVD then it's ok as you can see what you're getting and they can be cheap.

For anything else I would avoid like the plague.

The online side of it is dreadful. I ordered some RAM from them, but when it arrived it was the wrong thing. So, I dutifully notified them and opted to return it to them by recorded delivery which they said they would reimburse me for.
I waited. And waited. And waited. After a month I still hadn't heard anything (even though I know they had received my item). I emailed them and the said they were busy at the moment and would deal with it when they could. I pointed out that they had a legal obligation to resolve the issue within 30 days of me returning the product, which had since passed, and they replied that they'd do it when they got round to it. Several emails and weeks later the situation was the same, and so I said that I simply wanted a refund as I was going to buy the RAM from somewhere else.
3 months later I am still waiting for a refund for both the cost of purchase, and for the cost of my return postage. Keep getting nonsense emails fobbing me off. Infuriates me as I know that if I had taken something from CEX and wasn't giving it back I'd have the police round my door in a couple of days.
The long and short of it is that big companies are above the law and that the public are worthless cretins (in the eyes of companies and authorities).

I've stopped trading in games because every game I took in, the staff member would tell me that it was scratched (even though I look after my games extremely well and it was in the exact state that I received it off CEX a couple of weeks earlier) and thus they would only give me 50p instead of £4. I said forget it, but this has happened so many times now with perfectly good games that I think that it is merely a scheme to do people out of money as a lot of people will just say 'Oh, ok then'.

Avoid them before they screw you over, because sooner or later they will.