Lord of the Rings - It is still popular 15 years later. I know it is not a tournament game but not every game should be judged based on that. Deep rules with every mode feeling distinct. It is the perfect integration of theme and game.
AC/DC Premium - You could argue Metallica here or even The Walking Dead, but I think AC/DC gets the edge here. Lyman is still trying to tinker on the rules to balance everything and the premium adds to the experience unlike Metallica where it is not universally seen as a positive. The Walking Dead is great, however, AD/DC was the mic drop that announced Stern was back making great games again.