Following an “expert picks” segment on which teams will win the NFC and AFC championships – with the assistance of balloons – the “NFL Gameday” crew imbibes some helium and says random things. Warren Sapp does an impersonation of Jack Nicholson from “A Few Good Men,” while Jim Mora does an impression of his father (“do your dad!” “Playoffs?”!), but Joe Theismann stole the show with not one, not tw…