If you're looking for a no-fuss sleeve, have a look at Biolithic's Bags. That's not to say the sleeves are lacking in attention to detail: the interior of the case features real velvet for that smooth feel to go with your smooth MacBook. $42.90 USD will get you a sleeve including shipping outside of Australia.
Brenthaven's sleeve/bag hybrid could be considered the sleeve of choice for people that recognize the value of function over form. The light blue design isn't the most aesthetically pleasing design, although the thick padding along with the padded shoulder and the retractable handle will surely appeal to your practical side. $49.95 USD will get you one of these.
Fabrix Cases' sleeve falls heavily into the "trendy" category. Handsewn in a variety of styles ranging from stripy to polka dot to military camouflage, we can imagine looking pretty funky with one of these cases, although the absence of a zip for the top means your MacBook may be a little more exposed than you might have wished. $41.90 USD including shipping will bag you (ahem) one of these cases.
Some of Foofbag's made-to-order sleeves (pronounced "fooooooof") could possibly be considered "garish". Check out the Purple People Eater style and you'll see what I mean! If you're in the mood for a bit of a fashion statement, you'll need to plunk down around $49 AUS including shipping.
Mac-case's sleeve is arguably the best choice for a Mac lover. With the window for the Apple logo, you can display your Apple fetish with pride (from the confines of your real bag). Although it's not shipping until mid-July, if you pre-order now they'll send you a 14" case (which meets the MacBook's width dimension) and let you keep it once they send you the MacBook tailored version later on. $50 USD incl. shipping is the price.
Waterfield's sleeve is the ultimate build-to-order option. The basic sleeve features a neoprene cushion and a ballistic nylon shell, but if you feel like spending a little more you can choose a flap, shoulder strap and a piggback (that rhymed!). Otherwise you can expect to pay $56 USD including standard shipping.
Last but not least, Wrapper's sleeve brings an invaluable innovation to your lap: heat proofing. That's right, the sleeve's rubber exterior insulates up to 250 degrees C, allowing you to bring your MacBook back to your lap. Unfortunately, the case looks a little like an oversized oven mitt. £20.49 GPB for the ultimate protection.
If you're of the iBook owning female variety, make sure to have a browse of our earlier sleeve round-up.