VlaudTheImpaler
tl;dr
HWiNFO + Rivatuner OSD server is what I use. Probably the most customizable combo around since you can literally display any sensor that HWiNFO can read in the OSD and customize the layout.
Takes a while to set up tho
http://www.hwinfo.com/forum/Thread-Support-of-RTSS-Displaying-HWiNFO32-sensor-values-in-Games
Freaking thank you, I will look into it.
Even though I know my temps always hang in the 50's I get paranoid not being able to see everything.