I'm a HUGE advocate of the Avent Isis manual pump! I loved mine, and it lasted through both my boys.
Having said that, when I pumped at work I used one at the hospital. It was a Medela Symphony. I've also rented the same pump to keep supply up while dealing with issues on both boys as I was getting carpal tunnel manually pumping all day every day.
Anyway, what I'm going to get around to saying (after all that waffle
) is if you are working at a hospital that has a pediatric or L&D/post-natal unit, see if you can borrow a pump to pump with when you can get a break? I found the LC's were my best info source.