If you act quick, you can get a nice deal on an tablet from Newegg, which is offering 10% off a bunch of Android slates. It's not clear how many devices are included, but the new Shield Tablet is one of them (that's $30 off). This deal ends tonight—July 31st. Update: Looks like Newegg just removed the Shield from the list of tablets you can use the code on. Other devices seem to still work fine.
The page for the Shield Tablet lists the promotional code AFUBTB10, but it doesn't appear on all the product pages it can be applied to. In addition to the Shield Tablet, I've gotten the code working on Samsung's new Tab S devices, the Asus MeMO Pads, and the Transformer TF701T. And yes, it looks like you can apply it to multiple tablets in the same cart.
So check out the list of Android slates below and see what strikes your fancy. It doesn't include third-party sellers, and possible Newegg's refurbished devices.