Branson 2 for 1
This site consistently offers the best deals for the widest range of shows. You've likely seen their store on 76 with the big "no bull" banners hanging out front. What the building lacks in aesthetic appeal it makes up for with the deals contained within. They offer a wide range of shows, as well as a few hotels and attractions. Their offerings change throughout the year so check their website periodically.
Reserve Branson
This site does not have as significant discounts as the others, but it has the widest availability of shows and hotels. It also offers many good vacation package to peruse.
You'll want to sign up for the Springfield, Missouri emails. Like Groupon, Living Social also offers apps for Android and iPhones with paperless redemption. If you join using the above link you'll get $5 in deal bucks to start your deal hunting.
This site, operated by KY3, features daily, weekly, and secondary deals. Branson is featured on occasion in the daily deals, Clay Cooper and Montana Mike's were on the recently for example, and they have a specific section for Branson deals.
If you are interested in Branson vouchers, you'll want to make sure to sign up for the Springfield, Missouri e-mails. If you have a smartphone, Groupon offers an App for Android and iPhones allowing you to save some paper by simply showing your deal using your phone.
KTLO Discounts
Hometown Radio Auction Block
KHOZ Bids for Bargains
These three sites are operated by radio stations and consistently offer deals on Branson showtickets. All three usually have some good choices, but KTLO seems to consistently have the most shows.
Branson Bargains
Operated by the Branson Vacation Channel. The discounts are not as significant as the other sites but it includes several restaurants and businesses that don't typically appear on other sites.
Half Price Rewards
Offered by KOLR 10. This site focuses on Springfield deals, but does regularly include Branson businesses as well. The discounted certificates are made available at 8:00 AM every Thursday. Some of these do go very quickly so if you see an upcoming deal you'd like, try to be on at or around 8 if you can.
Missouri Bargains
This discount site is also not focused on Branson, but it does have the occasional show discount available.
Deal Chicken
A discount program run by Gannett, which is represented locally by the Springfield News-Leader, Deal Chicken frequently features Branson deals.