As sometimes happens, an original poster question turns into a discussion among the community and the original poster seems to have stepped away from the Stammtisch.
That said, my current daily driver is a 1990 Ford Bronco II 'truck' that I always prefer to take over our more modern 2008 Volvo C70. I just get a better vibe and a lot more joy out of driving that Bronco, even on the Southern California freeways where I can barrel along at 65-70 miles an hour all day no problem. The mileage is not quite as good as the Volvo's, at around 19 MPG, but it's ok. It's comfortable, although the A/C does not work yet (I just roll down the windows), it runs quiet and is quick enough for my taste.
So, for me at least, a 1990 car/truck is very much daily driveable.
I think there is a 'cut-off' point in technology before which the comfort, driveability, safety and everything else is not up to today's, and most peoples individual, standards and maybe that's still a bit before 1990 for most car manufacturers and their models (you need to look at when a model was first developed and marketed, the applicable technology generation which of course does not go by build year). The 1985 Nissan 300ZX we had last year was also quite a comfortable and capable car, so I do think for me at least that cut-off point is a bit before 1990. Maybe it coincides with the introduction of electronic fuel injection, stepping away from carburettors and mechanical. This would probably be the same time as the introduction of ECUs and the related technologies. Although come to think of it probably not, since my 1971 Volkswagen 411 has electoronic fuel injection and the associated brain and sensors, but I don't like driving it that much as it's too spartan for my spoiled taste...