My fondest memory from GT1 would have to be the FTO LM in green... Easily the best car in the game.
I remember entering a local GT1 competition organised by my friendly games store. Only about 30 people entered, but over the course of several weeks, we would all gather in the store and have a 5 round knockout with every other player. We had our own choice of car, but tracks were pulled from a hat at random. Each race was 5 laps.
I was unbeaten and had won every knockout tournament I played using my black FTO LM... but there was this young kid, only about 16 who I hadn't noticed as his rounds were always at different times to mine and he'd always won his games too. We finally met on the last day and 3 times my worst track came up, and he kicked my ass 5-0 with his green FTO LM.
Nothing to do with the colour of the car, it was all down to driver skill and car setup.
Needless to say I bought the car of him for my collection and challanged him to a fun rematch using untuned stock compacts... and beat him 5-0 on some of my more favourite tracks.
So I came 2nd in the tourney, but exacted some revenge when our cars were even.
Great fun and memories... GT2 was good, GTA3 was ok... no longer own a PS of any kind... and leaning more towards the Xbox360 as Forza on my old Xbox was seriously cool and more than a match for GT.
If I could, I'd buy them all.