I use Reg Mechanic and have total confidence in it.
I tried RegscubXP which was so vigorous it required a system restore in safe mode to get me back in business. Also tried regseeker and even only deleting the green items it was found to be far too vigorous for my system.
Just out of interest I recently downloaded and ran 4 of the "paid for" registry cleaners which you can find on the net. You know,the ones which will only fix about 15 items,and you have to buy the prog to get the rest removed.
I deleted nothing with each trial run and all four came up with four wildly different sets of results.
That alone tells me that there is a lot of myth and scaremongering going on with many of these progs.