I have had several meat thermometers, including the brands suggested above. From what I have experienced, you get good ones or you get bad ones. The bad ones are often easy to identify -- one measured raw chicken at 200* just after it was placed on the grill, several others just said "Hi" or "Lo" after a few uses. But even the good ones seem delicate and break if the wrong part touches the grill or if it is cleaned in the wrong way or... Read the reviews on
Amazon. People seem to love 'em or hate 'em.
I personally have been 100% satisfied, though, by
Thermoworks products. I am not affiliated with them. Every thermometer I've bought comes with a certificate of calibration and accuracy. I have the superfast
Thermapen. It is truly instant. I also have two smokehouse penetration probes with the stainless steel overbraid that is good to 482*. A stainless armor one is good to 662*. Frankly, I've found the probes to be just as fast as the
Thermapen, but maybe I'm just a bit slow. These things measure the same temp within a fraction of a degree from (at least) 70* inside my house to 300* inside my smoker. Comparing meat measurements is a bit more difficult since the temp varies quite a bit at different locations, but at comparable locations the temp is never more than 5* different.
These things are a bit pricey at about $100 per thermometer, but they really work! And they don't break if you happen to look at them wrong.