The Thunder Ridge stainless steel are supposed to be good.
I have also had good luck with the Ruger Old Army nipples, except they do require a Ruger hex nipple wrench or a 3/16 nut driver to install. They are also shorter, and I made .015 thick shim washers (I had a lathe then) to boost them up to the hammer. A feature I like about the ROA nipple is the longer threaded portion which brings the flash hole face flush with the bottom of the chamber. The Italian, and Treso, etc have that face retreated back up the hole, and expose the chamber's threaded hole to powder fouling and hot gas.
The ROA nipples thread fits the Colt 2nd and 3rd gen and Uberti cylinder, not the Pietta.