I try to avoid eating in the Times Square area, but sometimes when people are visiting I go to Trecolori on 47th before a show. Damn good Italian food at prices that aren't as ridiculous as much of what's around it.
If you go into the Marriott Marquis Hotel, take the elevator up to the 8th floor. It's where the check-in desk and lobby are. Walk all the way around to the restaurant that has the big windows (I forget the name) -- the windows overlook Times Square, but you're 8 floors up, alongside many of the crazy flashing signs (you can take some fun pictures up here). The food is good, not very expensive, and since it's not on ground level you have to know about it to find it, so it's not that crowded. Most of the people are tourists staying at the hotel, but I'm a New Yorker, and find it a fun place to eat, with quick service. Also a very nice brightly lit, clean bathroom on that level near the elevators. Close to so many of the theaters, you won't be late.