D.B.
I use a laptop case from any retailer/stationery store because I keep the charging cable, the mouse, a pad of paper, and other basic supplies with me - it's like a briefcase but it's padded and has extra pockets for other things. I keep my cell phone cable in there too so all my electronics are together. If you get a sleeve, you still have to put it in something. If you are going to put it in your briefcase, that's another story.