Ok... So there's no reason to consider Test Drive for DOS (PC) to be a technical marvel of its time... Plenty of games around the same timeframe used the same type of graphics engine. However, what set this game apart was the use of licensed real world vehicles with their own individual stats, gameplay staged on public roads (as opposed to race tracks), and the need to manually shift your car in order to keep the engine from blowing up (or your windshield from cracking, lol).
The game wasn't very long, but somehow managed to get you glued to the PC for hours. I remember actually getting nervous when the radar detector would go off... It would get my adrenaline pumping.
This game set the stage for its sequel, which ironically provided the most of the cars this one did but as an "add-on", and it probably set the standard for future games using the same model (free driving on public roads) such as the Need for Speed series, and now Test Drive Unlimited, which mixes the MMORPG concept (Ever Quest, World of Warcraft) with a driving simulator.
A drawback of the PC version was its limited number of colors. The CGA version may as well be monochromatic, and the EGA version
made the cars look very cartoonish. In comparison, the Amiga version made the vehicles in the selection screen look amazing for a game that was released in the late 80's. Another drawback of the PC version was its use of the internal PC speaker for music/sound effects. This, however, became transparent after a while once you really got into the game itself. Also, once inside the car, the environment graphics were pretty much the same across the board. The vehicle interior had a bit higher color on the Amiga version but not too different from the EGA version. The scenery itself looked the same (it was probably ported directly to all versions).
I can't say this is the best game of its era, but definitely one of the most memorable. The 3rd in its series implemented rudimentary polygon-based 3D graphics, but somehow did not share the same fun factor and appeal as this one. Test Drive was simple and innovative in its gameplay, and that made it enjoyable. Definitely a game to at least experience once in a lifetime.