Well, I'm going to ignore that you said Denco, and offer some insight myself:
David Seaman is the best England has at the moment, but he isn't getting any younger or better.
Davids James might be better than Seaman, but he does not have the temperment to deal with the pressure of international matches.
Nigel Martyn is a good solid keeper, but he is inexperienced at the International level, and there are some doubts about his reflexes.
Richard Wright was supposed to replace Seaman, but he has performed terribly since moving to Arsenal and since leaving.
Paul Robinson is young and improving, but he is not quite as good as Seaman, and he needs more international experience.