Is it a summer tent you're after or a winter mountain tent?
I personally use a Terra Nova Superlight Voyager. It's a superb 3 season tent (4 at a push), very well designed, very light yet strong, simple to put up, can handle very strong Highland winds if you use a bit of common sense when locating a pitch site (although it is known as a bit of a flapper), plenty room for two and a collie. I've used it down to -6 with no trouble, dunno how well it would handle in an extremely exposed spot, might be interesting.
We only ever go in a camp site occasionally if I can help it, but when we do it's always one of the smallest there
you can tell a lot about a person by the size of tent they use.
There's some cracking tents available too, some very pricey, it all depends what you're gonna use it for, people tend to have a separate tent for campsites where weight isn't that much of an issue and another for light backpacking expeditions. You can get a decent camp site tent for <£100, there's also decent backpacking tents for around the £100 mark, like the Wild Country tents, which are made by Terra Nova. You've got to watch the weight with backpacking tents, 1KG feels like half a ton after you've been walking with it on your back all day
Have a look at Go Outdoors, see if any fit the bill