Hybrid SyntaX: Your E6600 is an early revision B2 processor which uses a TjMax=85C. All temperature monitoring programs agree with this so you won't see much difference from one program to the next.
Your processor only has 2 cores so there is no need to use either:
Idle2=1
Idle3=2
Those are for adjusting a Quad core processor. You need to spend some time reading over the documentation before setting any Idle calibration factors. It fully explains what needs to be done to increase the accuracy of RealTemp at idle.
http://www.techpowerup.com/realtemp/docs.php