I use a Hanna Champ pH tester and a Sun Leaves TDS pen meter.

I agree that the Hanna is junk, but I have dropped mine off my hydro table (2 ft) onto cement a handful of times and it stays working. However, I am on my second meter because the first would no longer calibrate. I had to calibrate it every 2 days, and after about 5 weeks, it got to the point where I had turned the calibration screw down too many times and could not be turned down anymore. Luckily, I exchanged it for a new one at my local store. My new one stays calibrated for about a week and goes up a lot slower. Might have just been a bad meter, but I would say if you can afford to, stay away. It IS the cheapest pH meter available, so you get what you pay for.

My SunLeaves TDS meter is awesome. It was also very cheap and hasn't failed me yet. It also hardly ever needs calibration. I've had mine for a couple months now and I have only calibrated it like twice. The first time it read a 1K solution at 980 and the second was 1040. Its also very durable and has been dropped off the table more times than the pH meter.