Does anyone have any recommendations for work bags that will hold a heavy laptop and other stuff. I have expensive bags such as a Bayswater but I don't want to overload them and ruin them with heavy things so I either want a nice bag (not cheap) that won't get ruined carrying lots of stuff or something cheaper that will hold everything but still look smart. Ideally black or brown leather and will go over my shoulder, zips up, my laptop is 15.4 inches.
Budget is flexible.