What makes a good wine bar?

There was recently an article in the RFT about the nine best wine bars in St. Louis:
http://blogs.riverfronttimes.com/gutcheck/2012/04/best_wine_bars_st_louis_2012.php

In the event that the link is no longer valid, I do want to capture what they were:

• 33 Wine Shop & Tasting Bar 
• Remy's Kitchen & Wine Bar 
• Bridge Tap House & Wine Bar  
• Sasha's Wine Bar  
• Pomme Cafe & Wine Bar  
• Ernesto's Wine Bar  
• The Wine Press  
• Robust Wine Bar  
• Vin de Set

(I have not yet been to Bridge, but I have been to the rest.)

It got me thinking-what makes a good wine bar?  About 2 or 3 years ago my wine club visited a wine bar a month - we didn't hit them all, but the basic requirement was they needed to have at least 15 options by the glass. Selection/ variety is important, probably the most important thing, in my opinion, in a wine bar. But what else makes a good wine bar?? How big of a difference does price play? What about the price per glass/bottle ratio? Food selection/ambiance? What about a combo wine bar/wine shop - does the option to purchase a bottle at retail (either with no or minimal corkage) and drink it there intice you or turn you off? (like St. Louis Wine Market or Balabans) Are things like quality of glassware/variety of sizes for different wines important?