Jump: Space
Drop: P
Chat: T
Sneak: Shift
Inventory: R
List players: Tab
Zoom (if you have it): V
Drop is P, for obvious reasons. Inventory is R, so that when I run, I don't accidentally open my inventory, while still keeping it easily accessible for my left hand. (I rarely mess up running like that, but it does happen, so this is just to make sure I don't mess up all that bad when it does.) I have V as my zoom so that I can easily reach it with my thumb, however I never really use it that way, I have it binded to an extra button on my mouse. (I don't use Left-Ctrl because that's my TS push to talk, which I use since I commonly have a noisy background. I as well have push to talk binded to my second extra button on my mouse. I'm using a Razer Deathadder mouse.)