I used to love the upper back pop I could get from school desk chairs but I haven't sat in those in years so I have to resort to other measures. I can easily pop my lower back just by twisting, either while sitting or while lying down. The only way my upper back will pop is if I have help. Thankfully my fiance is willing to pop my upper back for me by hugging me and lifting me up.

My neck is by far the loudest. I have had people look up from across the room when I get a good one. My fiance is insanely jealous of my ability to do that!
My fingers are probably the most annoying to people around me because it takes the longest to get all the knuckles popped.

I am also amazed that this forum exists. I saw an article today on MSNBC.com about strokes caused by chiropractors manipulating patients' necks and wondered if the same danger exists from self-manipulating the neck. When I searched for more information, I found this site. I have popped my neck and numerous other joints for years (not even sure when I actually started).
I pop my neck several times a day, sometimes just by tilting my head back and forth. I pop every knuckle in my fingers constantly, usually without even realizing I'm doing it. Also, I pop my toes, elbows, wrists and back regularly. My ankles, knees, hips and shoulders will pop occasionally. I'd like to be able to pop my tailbone and sternum. A good friend of mine does it regularly and says it feels great.
It's nice to know I'm not the only one annoying those around me with the noises I make with my joints!