When it comes to restaurants Bangkok wins it from Pattaya by a country mile in my opinion. Pattaya for me is a bit of a culinary desert whilst the possibilities in Bangkok are endless, from simple inexpensive food to Michelin starred restaurants. Recommending restaurants is always a bit tricky though as different people value different things, but I'll take a stab at it...
Since we're in Thailand I'll start with a Thai restaurant. Osha on Wireless Road offers terrific Thai dishes in a very pleasant setting and is surprisingly affordable. Great place to take a date with a good value for money factor.
http://www.oshabangkok.com/osharestaurant/
Masu Maki on Sukhumvit soi 39 is a very simple little restaurant that serves high quality sushi for very reasonable prices. Perfect for a quick lunch or simple dinner, not so perfect to bring a date though. You'll struggle to spend more than 1000b here which for Sushi is a great deal.