Reigate High Street has a few good places:
The Dining Room - is the 'poshest' - upstairs above 'Si' italian restaurant. People 'dress up' to go there - expect to pay at least £45-50/ head for dinner. The food is fab though - Antony Tobin is/(was?) chef & owner.
Food is 'modern English' I think - in reality a good mixture. Probably not so good for veggies...
Gurkha Kitchen at the end of the High Street does great Nepalese food - more informal - quite busy, vibrant atmosphere.
Sweet Potato, around the corner at end of High Street, is a fairly newish restaurant - modern-ish stainless-steel/ wood decor. Michael Winner was there a couple of weeks ago and gave some aspects of it a good review... couldn't bring himself not to complain about something of course...
Otherwise there's French La Barbe on Bell Street (bit stuffy I always think...) or the traditional oak-beamed Italian, La Lanterna which is below La Barbe and very homely with huge portions of steaming pasta and VERY friendly staff...
Sorry, but Redhill simply has no decent restaurants. In fact, I wouldn't say that Redhill had anything that even classified as a restaurant, let alone a decent one!
Other thought would be Cloisters Restaurant at Nutfield Priory - been there a few times - good for family get-togethers as they have discreet alcoves for you to get pissed in together!
HTH