Hybrids are pretty much never a bad thing these days, and here's my newest favorite cross breed: Kolo Bags' quilted laptop brief. It's as slim and small as a sleeve, but with a handle.
This makes perfect sense to me, since my problem with sleeves is that they weigh down the larger bag I throw it into, hurting my back (yeah, yeah, I'm old) — and the problem with laptop bags that I have is that it's usually the same size as my big handbag, and instead of throwing all my stuff into the one big laptop bag, I insist on carrying both. With this bag, I could hold my laptop separately but avoid straining myself!
But enough about me, let's talk about this bag: Kolobags' little star comes in taupe, navy, red, black, or yellow quilted nylon with a leather handle, for just under a hundred bucks. Plus there's a (well-intentioned, if anything) lost tag on the inside, if a good Samaritan steals your laptop.