Having a bit of trouble with that mate but I'll try to answer what i think is your question.
For starters No serious Sim racer mentions consoles in the same place that people are talking about PC Sims.
As far as which one is best that is very debatable & Totally down to the Individual. You have a choice of 2, Either RFactor or LFS S2.
Don't get me wrong I love Forza2 & PGR4 on my sexbox but they are Arcade racers not Sim racers.
I have No experience of GT5 but if console i would dismiss it just the same.
My personal fave is RFactor because of the many mods & unlimited tracks you get for nowt, Literally if you cannot find a Mod & a track that suits you on RF then there just isn't one that will ever suit you

I have been involved with the game for ages now & even got my copy for Free off the creator Gjon Camaj
Anybody that wants to challenge what i write here needs to go drive Nords in a 288 & then come back to chat