It's Brother's Bar and Grill

From U of I Wiki

It's Brothers, or Brothers as it is generally called, is a popular bar between Sixth and Wright Streets on Green Street. Brothers is located on the second floor of a building, above Pita Pit, and is two floors tall itself, making it one of only a handful of campus bars with two stories.

Brothers' fancier decor and harsh ID policies make it suited for a 21+ campus crowd, and also help it be a common gathering place for 21st birthday celebrations. The bar is a chain, with many locations throughout the Big 10 and Midwest; the flags that hang from its ceiling show all its current locations.

It is known for its attractive cocktail waitresses, who are always friendly and willing to assist, as well as its manager, Alex, who himself is known for being morbidly obese and never without his trusty beret. The bar never changes its music selection, having played the same three CDs for the past 3 years. "Black Betty," "The Devil Went Down to Georgia," and a medly of other crappy classic tunes will hit your eardrums upon each arrival.

Inside the bar, it should be warned, that one should never attempt to purchase alcohol for an underage individual or stand on any barstools. An imminent warning and quick dismissal will ensue.