Always decently crowded, Genna's is a really great place to get a drink. It's never too packed, but never empty and awkward. They have a lot of seating, so I've never had a problem finding a chair. And it's not so loud that you feel like you have to scream.
They have a good selection of beers. Awesome happy hour prices. I like the two floor layout with a bar on both. I like the outdoor seating (lots of it). Lighting is good - dark but not weirdly dark. I really like the chalkboard that lists all the beers upstairs.
Service: I've never felt the bartenders were all that friendly. They get your drink, you pay, that's it.
Environment: Not too pretentious. Not too college-y. Good lighting - not bright, but not DARK. Not too loud. Overall, very chill.