RF1 as a base game with no mods was very basic and simple.
the mods made it what it is, which is how we will eventually judge RF2.
I got on fine with RF1 straight off the bat, the feel was about right, the sounds and graphics have always been average apart from a handful of mods that were genuinely superb. But, you could pick it up and play, same as Race 07.
I would drag out Enduracers as perhaps one of the finest mods every created, so good it really should have been sold. Not necessairily just on physics, but the whole package, menus, loading screens, detail, sounds.
Physics wise F12007, F1 stock cars, F5000, GT Legends mod, F1'85, but by far the best mod for me was F1-1991. Singly, the most immersive mod I have ever played. I just kept playing and playing and playing. It was just difficult enough to keep you wanting more, and just easy enough to wllow you to get close to the quick guys.
I rate racing at Montreal for 10 laps in a Footwork Hart and trying to hold off an alien in a Benetton as my proudest moment! I managed it for 6 laps, before I lost it trying to close the door!
Some of the tracks aswell were superb, obviously Mid Ohio rates as perhaps the best, but even some of the content released in packages like the 1990 tracks were excellent.
One final thing, if you have this game, load up F1'85. The sound is the same in every car, but the physics are different. Pick a track like Adelaide or Jerez and try and do a qually lap on full boost. It will take you a long time to hook one up, but my word!!