Can someone please recommend a good weight loss routine for someone with highly limited time?

I recently moved into the IT field and...have become rather out of shape from sitting at a computer all day...I need to try to get back into shape and shed some of the pounds I've put on, but my biggest concern is time...I have 11.5 hour shifts plus a significant drive time, meaning when I get home at the end of the day, I have maybe an hour and a half for anything (dinner, reading, tv, etc...)

So what I need is, if possible, a quick (20 min?) workout I can do for weight loss...that's also quiet, as I get home late and don't want to wake anyone up (apartment, thin walls)