RJ's is one of my favorite places in town namely because it's pretty close to my house and they have very good barbecue, it's my chosen neighborhood bar. $25 for 5 beers and all you can eat ribs and wings during a football game is a great deal. RJ's also has a pretty good beer selection so you're not going to be forced to choke down Bud Light or Miller Lite. You'll be able to watch the Chiefs with some Free State on tap, Boulevard and Tallgrass. The bottled beer selection, while not wide ranging, is certainly more extensive than any other barbecue restaurant in town and more extensive than can typically be found in Mission (though I've heard the new bar in the former JJ's Other Place spot, Sully's, is trying to be a little more beer centric than its predecessor).
I'm not sure if this is the best deal in town, but it does seem really cheap for the amount of beer and all you can eat ribs (and really good ribs at that). If you know of any Chiefs gameday specials that rival this leave it in comments. The RJ's tailgate parties start 1 hour before game time.