Duckworth's is probably my favorite place, $2.50 pints on Tuesdays and an incredible selection of craft beer. Revolution Pizza and Ale House also has a great selection, I've heard it rumored that they are adding more taps as well...
I love the flying saucer. I use to go to the one in San Antonio, TX all the time when I was in the Army. Being a beer snob it's hard to find cool bars with a great selection of brews.
My favorite place is a small place called Vintner Wine Market, which is located in the Arboretum Shopping Center in south Charlotte.
Don't let the name fool you into thinking they only have wine. They sell hundreds of great beers. If you want to stay and have a drink, you can choose from the 16 quality craft beers that are on tap. That number may sound small when compared to Duckworth's 60 taps or Taco Mac's 140, but there are always great (and often rare) beers to be had at Vintner.
It's a shame that all these great places are so far south of Cornelius. The drive home always makes me nervous if you don't have a designated driver on board even if you only had a couple beers.