I don't see the appeal myself but others enjoy themselves.
Almost always has a cover even though almost none of the others do, the drinks are watered down, the music isn't great, and there's always a good amount of straight people. Roscoe's is another one I'm not really a fan of. Lots of dancing and after 2am it turns into a shirtless mess of humidity which is fun for some.
Hydrate is one I'm not a huge fan of personally. Definitely a good choice if you're just looking for a generic sort of bar. Sidetrack tends to draw a slightly older crowd, but it's easily the largest (two floors with like 6 bars and an outdoor area) and most 'vanilla' of the bars so to speak. I'd have to hear more about what you're looking for to give a serious recommendation, but here's a quick overview of the ones that people usually mention and I'm familiar with (following are all in Boystown, and I'll probably forget a few because of how many there are):
