Another vote each for; lying down, a sitting pose that actually looks relaxed, idle animation options, gait options, and being able to sit in a chair (either through an item action or the command, easier through the item).
For gait options (in addition to what others have suggested), I suggest hunching, stiff, efficient running (unlike the plodding characters do now), lunging, matching gait with another player, sailor's gait, broken leg(s), tip toeing (or "rocks in the heels of your shoes"), and possibly the M.C. Hammer shuffle, but I assume that would be too silly for most people to stand.
I want a proper "collapsed from exhaustion" emote; it's not sitting, lying down, or being dead.
Backhanding someone; an alternate form of the slap.
Having a mental breakdown; effectively a different animation that leads to the "collapsed from exhaustion" pose.
Having a seizure (probably only linked to status afflictions).
Lighting yourself on fire (requires a fire source, should act like escalating poison).
Giving someone the evil eye. This expression should either look hilarious, disturbing, or both.
Can picking one's nose be used with a lock pick from inventory? Can you kill yourself this way? Free lobotomies? Would your lockpicking skill matter?
Enjoy drink.
Enjoy food.
Pat another person's head, patronizingly.