Best cell phone with great signal capability for the basics?

I live on a Loft building and every time I buy a new "better" phone the signal gets worst. When I moved here I had a simple phone and no problem, but it has been discontinued. The problem isn't the cell company, because all my friends with awesome phones have the same problem here. I don't care about 3 or 4G, e-mail, internet, Aps, camera etc, etc. I just want a phone that will allow me to hear the person on the other side. I just want good signal and text. I have computer, Tab, PSP and GPS in my car, I don't nee this in my phone too.