If you're not absolutely horrible behind the wheel of a car, you should be able to handle GT5 with the driving aids turned on. In time, as you adapt and improve, you may eventually wish to gradually toggle aids off one by one, adjusting to driving without them, if you wish.
These were worthless responses. They're utterly oozing with fanboy bias. Any honest rating for the game wouldn't be quite so radiant.
This can't be the "best game that exists" because the best games are generally not racing games. If this is supposed to mean "best racing game that exists", that's a problem because there's superior offerings available on PC. If it's supposed to mean "best console racing game that exists", that's still a problem because there are several ways that Forza Motorsport 3 is superior and because not all players enjoy racing sims, so players enjoying something more like Burnout or Need for Speed versus more simulation-y games won't find GT5 enjoyable at all.
The "best racing game on a console" was a little bit better, but it still ignores stiff competition from FM3. While the driving in FM3 doesn't feel quite as good as GT5, it still does a pretty good job, but FM3 typically surpasses GT5 in pretty much every other regard.