In reply to The Lemming:
I've used DS Colour Labs in the past when I've wanted some good quality enlargements. Photobox quality of prints went off a cliff a few years ago when they switched machines. It's a shame as they used to be brilliant. I can recommend Bonus Print photobooks which are cheap (when you make use of their regular 50 or 60% off)and pretty good quality. Don't go for the gloss finish though, which I tried once and wasn't impressed. Bonus Print prints and enlargements however weren't any better than Photobox really - blurry, poor colours, bleeding of high contrast areas and blacks that definitely weren't anywhere near black (they probably use the same machines as Photobox!).
I've not tried Peak Imaging, but may give them a go next time I need some enlargements
Post edited at 21:48