One of the interesting things about having a MAME machine at the office is I get to see what games my coworkers like to play. (The machine is around the corner from my office, so I actually hear what they are playing.)
With a list of choices in the thousands these are the current favorites, in order of time played:
We have an older crowd at the machine, so tend to stay with games from the early 1980s. One younger guy does play Street Fighter once in a while, but not nearly as often as those three.
We are in the process of consolidating our offices with another division, so I will have to see if the games of choice change with the demographics.
Of course, the MAME cabinet was one of the first things up and running after the move. We have priorities!