They are both fairly respected. Just remember by the coin not the slab. But I would go with NGC because right now in china they are faking slabs and PCGS is refusing to release the specifications of their slabs that prove they are genuine where on the other hand NGC is. And NGC is like 50 cents cheaper. (PCGS sounds cooler though. ) EDIT: PM me when you get your coin store up or start selling coins on ebay. You are the one that deals in bullion right? Do you do ASE?
Silverstruck1 - just so you know, this topic has been discussed endlessly in several historical threads on here and other coin boards. You can use the search feature here to help you find them. You can also search on "TPG" (third party grading) for another term used. Good luck. Edit - here's a recent example: http://www.cointalk.org/showthread.php?t=39473&highlight=tpg+pcgs+ngc
Well, they are the top 2, but PCGS seems to get slightly more respect. And sometimes that causes coins slabbed by them to cost more money, which is why I like NGC.
It has always seemed to me that NGC is a bit more consistent with their grading when compared to PCGS...but maybe I'm just imagining it. I think they are both good companies but I don't put complete faith into the grades either assign.
