You don't have a whole lot to choose from, that are cost effective. The Enermax single for $14.99 or Dual for $22.95 are the biggest movers. These are not Lab grade devices, but they should get you within 1C of a lab grade device. Besides a static reading, they are not the best for tracking across a range of temps to a final resting point. They may read close at 25C and be off by a few degrees at 40C. I am fortunate that I have access to lab grade measuring devices and have calibrated my inexpensive Enermax sensors. One of the overclockers.com regulars got one that was off by 6C right from the get-go. The dealer replaced it for him, but the only way to know if one is out of whack is to have a reliable second device to compare it to. generally, the Enermax units are a safe bet, but they are not flawless. Considering the price they sell for, it's no small wonder.