No, I haven't and have no plans to go to any. I simply hate crowds of that size and the traffic jams before and afterwards. Always have. We have a group of friends who feel the same so we alternate hosting parties before and during each home and away game. Sort of, At Home Tailgaiting. :) Lots of TVs set up, plenty of great food, good company and no traffic hassles. For me, its a much better way to enjoy the game.
Of course, for really big games, like bowl games, when I often have access to skyboxes I find a way to amend my way of thinking. LOL
We go once every couple of years. We know ways to avoid major traffic, plus the spectacle of being in the most attended sporting event anywhere is too hard to pass up. The whole massive tailgate outside the stadium stuff, the bands, the warm ups, it's just a wonderful time. We plan to go to one late in the year.
Lately we do at home tailgating using a DVR. Start the game an hour late, fast forward through the ads and halftime. More time for partying before and after as well! No one who comes is allowed to look at game scores early........