I highly recommend the Medela Pump-in-Style. Have only ever used this, so I don't know how it compares with other brands, but I've used the Medela PIS with #1 and am still using it with #2. A worthy investment.
What's more, if you are going back to work, the Medela PIS comes with a cooler pack and bottles that you can use to transport the expressed milk back home. Very handy.