I've gone to Barrio for years! The best thing you can do for yourself is spend a happy hour here. $2 tacos can't be beat anyplace else.
I recommend the Jame-o-rita. It's not a happy hour option but if you're already receiving $2 tacos you can splurge on the rita.
My last visit was for Cindo de Mayo. I was apprehensive that we'd get a seat fast, especially during happy hour. But they sat us in less than 15 minutes.
OOh, and dare I add - GREAT people watching. I saw (and heard) a couple fight, she walked out on him, and he didn't even run after her. He just sat there and continued to eat his taco. (Which means the tacos must REALLY be THAT good.)
Priceless. Go for the people watching.