I personally wouldn't leave any gun in my car....my gun goes where I go.
I would put my "vote" in for whatever gun you woldnt mind being stolen from you. Everyone else will have a different opinion but I have had two vehicles broken into and my handguns stolen. The first time is an "oops" the second time I felt so stupid...
If your leaving it in your car while at work wouldn't it be your normal carry gun? I take it your work place has a "no guns rule" or you would not be leaving it in the car. Everyday many of us make a choice between carrying and our jobs. I've had to leave my Glock 19 and my Kel-Tec PF 9 in the car while at work. Once the work day is over they go back were they started the day. Other than normal cleaning I've never had an issue.
my gun only stays in my car wile i am at work, only because i can not take it in with me.