If I can't give the Key a 5 star rating, I don't know what I would. As a disclaimer, I worked there for 2 years and left on unsavory terms with the owner. The fact that she (wears the pants) and her husband are doing back-to-back prison sentences bumps it from a 4 to a 5.
Now, any bar in madison on friday or saturday is bound to be butts-to-nuts busy, so don't take away stars for it being packed, that's just dumb.
Drinks=strong.
I'd be hardpressed to tell you the prices, but I'm guessing they're average. Stick to specials and you'll do all right. In response to another reviewer... most male bartenders come off as tools, it's in the job description, and the Key's aren't on the same level as those at Brothers, Mad Ave or even (maybe even especially) the Nitty.
Food=Exceptionally good bar food+a ton of it+cheap.
A burger special is $5 and it's uncomfortable to finish all of it. I recommend trying.
If you're ambling towards Camp Randall or the Kohl Center, stop in for a quick round or two of shots. It's easy enough to get to the bar in a timely manner and it's right on the way for a lot of you.