I have several briefcases (too many if you ask my wife). I've had big name cases - Tumi, Briggs & Riley, Hartmann, etc,, and small company cases, but 4 products have really made me the most happy and are the ones I use most (depending on the occasion).
1: A Classic Briefcase from Mitchell Leather in Wisconsin. It is classic, made of amazing Horween leather and built to last.
2. A custom leather briefcase made in Wickett and Craig Bridle leather by a custom maker who unfortuntley retired. Going custom is great because you can specify exactly what you want.
3. A BOB Bag in Martexin waxed canvas. This is a soft side bag that harkened back to the old Land End canvas Briefcase when they still produced a quality product. Sadly the company that made the BOB, Modern Industry in San Francisco, closed up.
4. Pad and Quill's The Briefcase. I had been considering the Filson Original 256 Briefcase & some who haven't done their research will call the P&Q a knock-off. Compared side by side, it will be the Filson that seems like a knock-off. the construction is more solid and every place where leather is attached to the canvas is backed by leather on the other side through the canvas to distribute stress (the 256 only has leather on one side stitched into the canvas with no extra support on the other side). There are many useful inside pockets. The canvas is similar, but the leather on the P&Q is higher quality full grain. It also has a leather storm flap. This is my new go to bag for everyday use whether business or casual. I'll break out one of my nicer bags for formal business, but 95% of the time it will be the P&Q case.