Properly measuring my temps?

[muellerdillon]

When I OC I use a combination of Aida64, CPU-Z, and Open Hardware Monitor.

I'm running an i5 4670k @ 4.4Ghz at stock voltage(1.2v), so it OC's well.
What I want to know is what temperature sensor should I get my most accurate temps from, each single cores reported temp, or the CPU Package recorded temp, I;ve heard that the package measurement is a MOBO sensor that actually displays the same temp in the Bios and that it is actually fairly inaccurate, but I'm not sure, can anyone help answer this to me please?
i5 4670k @ 4.4 Ghz @ 1.2v
Asus Maximus VI Hero
Corsair H80i x 2 Corsair SP120 high performance (push-pull) set as an exhaust in the back.

Thanks to all in advance!!

PLEASE look at the screenshot, I want to know if to go buy the 4 core temps, or the single CPU Package? Which is more accurate?
http://s144.photobucket.com/user/Dillon_Mueller/media/Screenshot8_zpsdefe6d5d.png.html

 

[bnn]

use this instead http://www.techpowerup.com/realtemp/ i find it much better than hwmonitor