When I was a(n intentionally) poor volunteer in Cleveland, the Cleveland Public Library's main branch was a major reason I didn't go crazy. I came here many times a week, and although I usually ended up using the computers to read and write email, I also checked out quite a few books from here.
What everyone is saying about the building is true. Although it's not my cup of tea architecturally, it's impressive in the way it was meant to be impressive when it was built. And it's pretty fun to be able to walk up the marble stairs and feel like you're in a museum when you really just walked in off the street.
The reason it doesn't get five stars, though, is because its selection, while large, isn't quite what it could be. I guess I'm spoiled by San Francisco's Public Library. That said, I really do love the CPL, and I encourage everyone to check it out.