It really depends on the amount of brass you are planning on spending.
I would heartily recommend the Nikon D90 but that's not really that much help if you only have a £300 budget.

At entry / mid-range DSLR level, Nikon and Canon's are pretty much equal when it comes to picture quality.
I would recommend going to your local camera shop and picking up and handling the actual camera before buying.
I prefer Nikon because the build quality feels better than the equivalent spec/price Canon ones.
( mns 2️⃣2️⃣9️⃣0️⃣7️⃣, Sun 14 Jun 2009, 13:25, archived)

This.
I got a Canon because I was familiar with the controls, but an entry-level Nikon would have served me just as well. Go and pick one up, play with it. I hear Nikons can take older lenses though, so if you're on a budget that might be important.
( spangolin - the odds are good but the goods are odd, Sun 14 Jun 2009, 14:01, archived)