argos
For what? Summer/Winter? Walking/Car camping? 2ppl + living space/ storage space?
a bit more information would help tbh,, like where u r planning to use it? how often?
It's often a good idea to get a tent rated for one more person than you need - yes, you probably will both fit in a two person tent, but with whatever gear you're carrying, and having to move around and get changed it will get cramped pretty quickly. A three man tent just gives that extra bit of room.
It's hard to go wrong with Vango, especially if you're spending a decent amount on it (as in, not one of their low end models, something above £60).