I´m aware that this thread is to judge the sitting possition that PD placed in cockpit views, not how cool or terrible the car looks on the inside.
The best Premiums, I would say cars like the E92 M3, Nissan GTR, Gallardo, XJ13, Shelby Cobra and pretty much every car that gives you an overall good view of the road, as well as the steering wheel and dashboard details. The best would be the McLaren F1, simply because the seating possition gives you the best view than any other road car.
The worst Premium interiors, the LFA, Murcielago Golf GTi and others in which you seem to be "kissing" the steering wheel, plus they give you a very limited visibility. The Citroen GT has a good possition, but unfortunately, the speedometer was placed in the worst area.
As for Standards, there is no debate here... The Prowler (not only because it even has working gauges), but the open top gives you great visibility. The Super Seven has the best visibility in general, as well as the Tank Car.
Worst standards: the Bently with no doubt, and pretty much all of the "blacked out" ones, not because the lack of detail, but visual references. At least in GTPSP you had a clearer view of the car itself, and were able to judge the corners better, due to the fact that the car was visible.