The following guests are simply my guesses and ideas for who ESPN could pick, and are in no particular order. Please comment on any other guest picker ideas you may have.
Dwight Clark (Clemson WR 1975-1978) and Joe Montana (Notre Dame QB 1974-1978): Joe Montana and Dwight Clark not only faced off against each other in Death Valley in the 1977 Clemson-Notre Dame game, but they ended up being teammates in San Francisco from 1979-1987. The duo won 2 Super Bowls, and will always be remembered for Dwight Clark's infamous play, "the Catch," in the 1981 NFC Championship against the Cowboys to send the 49ers to the Super Bowl.
Nancy O'Dell (Clemson Class of 1990): The Former Miss South Carolina and current Entertainment Tonight host has been a very visible supporter of Clemson University. She constantly discusses Clemson athletics on her social media pages and has worn Clemson apparel, showing her pride in Clemson, on the set of her show multiple times. Nancy O'Dell would be a very well known guest host who also would be knowledgeable of Clemson and college football.
Lee Brice (former Clemson Longsnapper): Another Tiger that would be recognizable in the non-sports area, the country music star has had 4 #1 singles and multiple popular songs. Brice has done two shows in Clemson over the past 4 years, so assuming he has no scheduling conflicts, he would definitely want to come back. Gameday has a history of using country music stars (including multiple ones this year), so this would fit that trend.
Josh Turner (Clemson Fan): The Hannah, SC, native is a known Clemson fan and attended the App State game this year. This would also fit in with Gameday's trend of country music stars.
Bill Murray (son goes to Clemson, Charleston resident): He gave us this last time. That's all that is needed.
Brian Dawkins (Clemson Safety 1993-1995): Dawkins was the heart and soul of the Eagles Defense for years, and is now a NFL analyst for ESPN, so it would make perfect sense for him to be on Gameday. But, ESPN doesn't often make sense, so don't get too excited.
Kenny Chesney (fan of every sports team ever): When in doubt, bring in Kenny Chesney. That's Gameday's motto. I would be frustrated with this, but after getting Eric Stonestreet for Clemson-UGA in 2013, it wouldn't shock me.