At participating 7-Eleven stores, text "SIXFLAGS" to 711711 to get a coupon good for a free medium Slurpee. That ties last week's mention as the best free offer for this size this year. The coupon is only valid for 15 minutes after pressing the "redeem offer" button, so be sure to press it only when you're ready to redeem it. Deal ends December 31.
Before you send in your tax return, double-check that you haven't made one of these mistakes that can trigger IRS scrutiny.