I use a Fluke. I used to use a cheaper one, I beleive it was a GB. The problem with the cheaper ones (and it can be a problem with the better ones too) is that when going inside an enclosure to check for hot wires, a cheaper one will light up as soon as you get close and you cannot determine what is hot and what is not. These testers are not the final say for me either but can be valuable to seperate circuits etc.
