fun

More info would really be helpful. A car that is simply fun with 5 seats and costing less than $80k doesn't narrow it down much. What kind of driving do you do with it? Commute? Weekend rides, etc?? Do you need good mileage, or is this just a weekend toy? Cargo needs? Bad weather needs? Do you do much of your own maintenance?

Members are more likely to respond to requests that give a good solid list of criteria.

I haven't yet driven the new Alfa Romeo Giulia. Either one of these or the Cadillac ATS-V (or even the regular ATS; the V has so much potential you might not be able to have fun with it on public roads, depending on where you live).

Or, if you can find one under $80k, the new AMG C63 has been winning comparison tests. Another I haven't driven, though.

Shifting down a power level, the Infiniti Q50 3.0t Red Sport can also be a lot of fun. I like the optional Direct Adaptive Steering, but some people don't, so I'd test the car with and without the option if possible. With the option, be sure to check out the different steering modes. The quickest is ultra-quick.