Several months back I had to switch from a Mac to a PC. I am pretty much OS agnostic and really feel both Windows and OSX have their strengths and weaknesses. I also think Linux is great, but the lack of Adobe products is a show stopper for me.
That said, after the switch, the one thing I really missed from the Mac was the ability to see file thumbnails in the Finder for almost every file type. I recently started using the Adobe Bridge as my new Windows Explorer / Finder at work and it works like a charm. Even on the Mac sometimes files would not preview, but with the Bridge pretty much every Adobe file type previews. This can save a lot of time when looking for the right file in a sea of mockups and layout files. I think the Adobe Bridge is one of those underappreciated little apps, so if you need to see your files before opening them, give it a try. There is a little slider at the bottom that allows you to change the size of your previews too, which is really helpful and I usually make them quite large.
The Bridge goes much deeper than this, and has many other features which I have not explored yet. Some capabilities are filtering, sideshows, content management with version cue, and total integration with the Creative Suite. I plan on digging deeper into this great application, but for now the basic ability to see everything I want to see is more than enough reason to use it as a standalone file browser.