I must really like my job. Every morning for work I wake up at 5:30 and drive 30 miles. I start the day with the droning messages from patients who have had "an emergency" (most of the time this means they have a pimple). Then the patients arrive, and arrive, and arrive. We finish for our 30-minute lunch break 15 minutes late so we then shove food in our faces and get ready for the afternoon set of patients. Then at 4:00 the work day is over. Thank God!
Even with this bleak outlook on the day's events my most common default mood at work is one of happiness. The people I work with are fantastic and since we are all in the same boat we try to keep the office atmosphere happy and anger-free. This is probably the most unlikely mood that I should experience at work but it is the most common.
Another mood that often crosses my mind at work is that of disbelief/amazement. The patients come in with some ailment and we tell then what they need to do to fix it and send them home. Two weeks later they return and are complaining of the same problem. When you ask them, "well did you do what we said?" the answer is always "Oh, I didnt realize you wanted me to do that." It's not like we didn't send them with written instructions. 
Then there are the tanning bed queens who come in at age 20 and have a glorously brown tan. They hear the "tanning-bed speech" but answer "well, that wont happen to me, I wont get skin cancer or wrinkles." 5 years later they come back wondering why their skin looks so old and I just shake my head.
The final mood I experence is empathy/sadness. This occurs when I have to tell a patient they have an advanced form of melanoma and the prognosis is not always good. The disbelief that these patients fele is so profound it could affect anyone.
So in my carrer I expereince a full range of moods from highs to lows, some of which are not always expected.
alarm clock avalibale from www.global-brb-network.com
http://publicaffairs.uth.tmc.edu/hleader/archive/Dermatology/2005/freckle-0610.html