We will have to agree to disagree.
I'll just have to disagree, then.
I think GT4 crashed in the middle of one race, out of about 15 months of gameplay on my PS2.
In the early days of Spec I, Prologue would occasionally crash either entering a network race or leaving it. After Spec II, no problems. There are the shadow issues as has been mentioned.
With Forza 1 on the XBox, it would periodically crash. It would sometimes crash four times a day, and then go three weeks with no problems.
In my first race in FM1, the screen froze upon crossing the finish line the first lap for one or two
very long seconds, and would still do it on occasion.
There are livery glitches on the surfaces of some cars which invert patterns and decals, and it's very hard to make things right, sometimes you can't.
With Forza 2 on the 360, I've crashed several times out of the blue for no reason in eleven months of play, though less than FM1 on the XBox.
Every third scroll through the garage (I pause several times, hoping it won't) causes the game to crash.
Occasionally, the Auction House will cause the 360 to crash, and if they didn't fix it yet, this can result in a ban from Live.
The physics have had to be patched several times due to bugs and unfair performance loopholes, resulting in unpopular leaderboard wipes.
The Livery Editor is buggy as an old house. After an hour of use or so, I can't rotate elements back to zero, or straight horizontal or vertical. It goes off by a decimal point, and just gets progressively worse. I have to save and completely shut down for a minute. It will occasionally crash, and all unsaved work is gone. Liveries shift around when you go out for sometimes just one race, or for a photo shoot. If you don't fix it - assuming it's not locked and you can fix it, they continue to shift around. Locked liveries eventually become a mess, and you'd better hope the original artist is in the mood to take it and fix it for you, or have mercy and unlock it. The same surface glitches on some cars are in FM2, and more.
I could go on, but I'm tired. Disagree all you want.