Sabertooth Temperature Sensors. Where do you place them?

[kodi]

The Asus Sabertooth motherboard comes with three temperature sensors and I was wondering where people who have the board have placed theirs.
Some research has shown that some users don't use them and others have all different locations.
What is your opinion on placement?

 

[madcratebuilder]

Lot of options, cpu heatsink, gpu heatsink, ambient air, memory sticks are a few. CPU and GPU are better monitored with software. In one box I have sensors on the Northbridge, PSU and ambient air, another has coolant temp in and out of rad, ambient air, memory sticks, rad fan air in and out.