You haven't really said how wide and for what purpose, whether you want zoom or prime. At £200 you aren't likely to get anything that is pin sharp wide open but it's also how fast do you need it to be. You will of course get varying opinions based on peoples experiences but if you were a little flexible on your budget you might want to look at Nikon 20mm f2.8D, 24mm f2.8D, Tamron 17-35 f2.8-4 (mine was excellent but some people have had them soft - read the reviews), Sigma 12-24 (a bit slow but depends on planned use). I found the Sigma 14mm f2.8 to be great but distorts rather a lot. The older Nikon 20-35 f2.8D zoom was a pro lens, usually found well battered but bloody excellent. Might give you some ideas.