It depends on budget, and sometimes where you're based.

Take a peek at NYBannerStands. Their site is a bit...uhm... suspect, though they're excellent. They offer fair pricing, great print quality, their vinyl banners are top notch, grommets and reinforced edges are standard and their turn around time is lightning fast. They can also print just about anything related to booth / trade shows, and do vinyl and fabric printing.

If this isn't quite your fancy, check for some local print shops in your area. Avoid Kinko's or the big chain printers, it's not the people's fault that work there, they just won't be as knowledgeable as someone working at a legit print shop.

Good luck!