For retro,
Mazda R100, RX-2, RX-3 or RX-4 coupe. I'd also consider the first or second generation RX-7 - maybe a Turbo II (Series 5) RX-7.
I have to say I do like the early 911s style wise but I've never seen myself being a Porsche driver if I'm honest. I feel like it's more fun to poke fun at them .
I love the old RS Camaro (67,68) era, or 68 Mustang Fastback. But I absolutely adore the 63' C2 Corvette Split Window. But they are uber expensive now so not something I'd be driving I'm afraid.
I'd say if it wasn't a Z it would be a rotary coupe for sure. Or keeping it Nissan I'd love a 240K coupe (as a GTR clone).
For modern...
FD RX-7 for me is the only way to go if you're looking for a car that is comparable to the early 240z. The styling hasn't aged, it's a 2 seater coupe, I just love the wide stance from the rear of the car, the dashboard feels like a cockpit (Just like the 240z) and the rotary is a super cool motor. Mine has the air-con, power steering, stock exhaust so its quiet and it's about the only other car I've driven where I look in shop windows to see how cool the coupe looks (I do the same in the 240z).
I've never driven a GTR, would love to some day, I think the S15 Silvia is also nice looking, but too many boy racers in them these days.