This depends entirely on who you are, how shallow you are, and what you want to signal with your car. A few options:
If you view your car is a status symbol and want to show up your classmates, pick any mid-engine exotic supercar (Lamborghini, McLaren, Ferrari, or C8 Corvette). It doesn’t matter, you’re just showing off. Bonus points if you wear attire with the manufacturer’s name/logo on it so everybody knows that you’re the Ferrari guy when you’re not actively being seen in or near your exotic.
If you view your car as a status symbol and want to show up your classmates, but want to appear slightly less flashy, go with a 911 or Aston Martin.
If you view your car is a status symbol and you want to seem practical while showing up your classmates, go for a luxo-german-barge (S-class Benz, 7-series, Audi A8/S8, or a Bentley if you really need to rub it in). Also acceptable in this class is an ultra-high-end SUV (Aston, Bentley, etc).
If you view your car as a status symbol, want to show up your class mates, and you’re a techno-nerd consider going higher-end electric (Tesla Model S Plaid, Lucid, Taycan, etc).
If you view your car as a status symbol and you’re a bro, then there’s no substitute for a bro truck. Anything less than a 3/4 ton truck is unacceptable – you won’t look wealthy enough in a half ton truck. Having a dualie helps. If you’re under 40, you’ll need at least $20k in mods to lift it and have low profile tires that extend beyond the body to let everyone know that your $100k+ work truck is not usable for anything resembling any kind of work.
If you’re going to the reunion to show off your large family, a practical full sized SUV is ideal (Suburban, etc).
If you want to show off your family but also want to show off your disposable income, a higher end full size SUV will work (Wagoneer, Navigator, Escalade, LS 470, Range Rover etc).
If you’re Martin Blank and are a professional killer, there is no substitute for a rented 1997 Lincoln Town Car.
If you don’t live in the same town and don’t need to show off, fly in and take an Uber or get a crappy rental like the rest of us.
There, everybody’s covered.