Update May 21, 2013: This deal has expired and the price is now $30. That’s still a better deal than the full retail price, but not as good as yesterday’s price. Thanks and congratulations to all of you who were able to take advantage of it.
I’ve been using the Logitech T400 Touch Mouse for a few months now, and it is, by far, the best I have found for working with Windows 8.
You can customize its settings using this very intuitive app, which Windows 8 automatically downloads and installs after it detects the device.
And today it’s on sale for $20 at Amazon, which is half its normal price and an absolute steal. I’m tempted to pick up a couple as gifts.
Logitech Zone Touch Mouse T400 for Windows 8 – Black (910-003041)
Highly recommended.
Disclosure: I get a commission from Amazon when you use the affiliate links on this page.
Ed Bott (@ wordpress.com) 
Just snagged one with my Prime membership. I’ve been lusting over this mouse and got an offer from Logitech, but this was the much better deal. Thank you!
Devices like this are what make W8 a lot more usable on older systems. I’m still using a Dell Dimension C521 that I bought in 2004 or 2005. It’s a little sluggish occasionally, but all I need for web surfing and general use. I don’t have this mouse, but something similar and it completely changed my opinion of W8 on a system without touch.