One year I renewed my lease in this crappy building...I knew perfectly damn well I was living in a slumlord building but my desire to, for once, have a year where I didn't have to move outweighed my desire to get out of the building.
It seemed like the moment I signed a lease for the second year, shit started to go absurdly, comically wrong. I was in grad school at the time, and my favorite is that I came back from a summer internship in DC to discover that it now rained in the elevator when it was raining. Go figure that the elevator was constantly breaking down in this second year.
And this was a 12 story building. There were a lot of elderly people with walkers/etc living in the building. They were basically trapped upstairs without the elevator. I was in really good shape at the time, and it was still miserable when this happened because I lived on the 10th floor.
To give you the full flavor of this building, one time I came into the building right as the super was about to put the elevator out of service so he could repaint the exterior door. It will soon become relevant information that this was a Russian guy, probably 6'4", with a potbelly.
I asked him to just let me pop up before he started, since he hadn't actually started yet. He refuses. Then some other tenant walks in and he lets her get on the elevator. This really sets me off because now it's clear that this is very specifically about not letting me on the elevator. The son of a bitch actually pushes me into the (rather small) elevator, and we start going up (with this other tenant in the elevator), and we're standing uncomfortably close to each other yelling at each other and he flat-out says "shut up or I'm going to punch you in the face."
I hated having to pull this card, but my dad is a lawyer. He wrote the landlord a letter on his law firm letterhead saying, basically, "I'm Eurynom0s' father but I'm writing you as his lawyer. If this ever happens again I'm suing you for everything you're worth." Go figure, after that, I only ever had to directly deal with his wife up until the day I moved out.
Also, if you have any friends or family who are lawyers and you're having a problem with your building that isn't getting solved by normal means, ask them to write a letter to your landlord that contains an implication that you're willing to sue them and that they'll represent you for free. Do check if they'll actually do it if it comes to it, but the point is it's a really good bluff--the landlord is going to pay attention if you're throwing down that you won't have to pay for your legal representation if you sue them, because if you can sue them for free then you're way more likely to actually do it.