Both are rivals. But gotta say vandy. If they win this year it will be the first time they graduate a team that goes undefeated against Tennessee since when? WWII? WWI? The war of northern agression???
Recent history says Vandy, but I'm definitely in the camp that feels like Kentucky is more of a rival. At least Kentucky *tries* to field a legitimate football team and has actual fans that show up to their games. Vandy doesn't feel like a rivalry to me because no one gives a crap about Vanderbilt football.