Minneapolis has a lot of great venues even if you aren't looking for a tradtional 21st birthday.
So where to go?
- The Parlor - Great cocktails (no beer on tap, just cocktails) and an absolutely amazing burger. Not familiar with cocktails? The ultra-friendly staff will make suggestions to find you exactly what you want. It's my favorite bar in the city. Expect ~$12 per drink.
- Marvel Bar - This is a great place to go for that exclusive hidden away feeling. Get there early (before 7) or risk not getting let in at all. You actually have to walk down/below/behind Bachelor Farmer and talk to the two guys at the corner to get in. No signs. Super neat vibe. Prices are similar to The Parlor or just above.
- Bulldog on Hennepin and 11th - Because you want decently friendly service and a wide selection of tap beer at a decent price.
- Kitty Cat Klub - Go here if you've ever had to deny being a hipster. It looks like what you'd expect from that guy who always threw awesome parties in college where they always had super obsucre music playing and weird lighting and everything seemed to be in this weird space between charming and falling apart and he swore he'd open a bar some day.
- The Local - Because it's a staple, it's in the heart of downtown, and it's cool. Just get there at some point. The chicken shooters are amazazing. Oh, and if they still have Fruli on tap, ask for the black velvet.
- The Triple Rock Social Club - Because you want to hear weird fringe music and the word "crusty" excites you. Cheap amazing shitty food.
In addition to these I would throw the following on your list:
- Club Jager and/or Bunkers - always music
- Psycho Suzi's - just awesome in all ways
- Donnoie Dirks Zombie Den - Its a zombie bar, so why wouldn't you
- Jackson's Hole - the place is always dead, so if during the night you need a break from chaos and want to sit down, this is the place. Also they had restaurant.com gift certs that could be used for booze.
Pancho Villa is an ultimate 21st bday destination.