Buy one Snickers Candy Bar and get a second Snickers Bar (of equal or lesser value) for free via this printable coupon available from Snickers via Facebook. (To get the coupon, you'll need to register your email address and complete a short quiz.) That's a savings of up to $2 and a rare discount on these candy bars. You can print the coupon up to five times per email address. Deal ends July 31.
Note that it requires you to install the Coupons.com printer to access the coupon.