Detroit has one of the most underrated sports ecosystems in the country - every franchise shares the same tight downtown footprint, and each one has its own specific culture worth knowing about before you show up.
The Loudest Dome
Ford Field is one of the loudest indoor NFL stadiums in the country when the Lions are good - and lately, the Lions are good. The dome traps everything: the noise, the energy, the collective belief of a fanbase that waited a very long time for something to believe in. Pre-game at Checker Bar two blocks north on Cass Avenue - double cheeseburger, cold beer, a crowd that's already loud before kickoff. Section 105 in the lower bowl has the angle where you can see both red zones.
Summers at Comerica
Comerica Park is the summer destination for Detroit sports. Tiger statues flank the main entrance, there's a Ferris wheel and carousel in the outfield (you'll ride the carousel, admit it), and a summer afternoon game against a division rival with the sun at your back is one of the better cheap afternoons available anywhere in Michigan. The food situation inside has improved dramatically - Brushfire Griddle near Section 137 has the best burger in the park.
The Underground City
Little Caesars Arena handles Red Wings and Pistons in the same building. The Wings have six Stanley Cups and an octopus-throwing tradition during playoffs that is genuine Detroit: somewhere in the history of this franchise, someone decided to throw an octopus on the ice as a good-luck symbol, and this became normal. It still is. The arena connects underground to the Fox and Fillmore, which means on a big playoff run the whole District Detroit neighborhood is one interconnected party.
For a pilgrimage worth the 45-minute drive: Michigan Stadium in Ann Arbor holds 107,000+ people. A Saturday Big Ten game in the fall with a full house is simply a different class of experience. Evil Tickets has Lions, Wings, and Pistons seats whenever you're ready to make the trip.