I think there are really only two major players PCGS and NGC but there are a couple others like IGC and ANACS but would generally call them a tier two TPG but i know some people use them to protect there coins but using them to increase value maybe not as much. For me anyway i have always preferred PCGS as the value of there slabbed coins always brings a premium over NGC and the others, plus i have never liked NGC slabbed coins just think ther to bulky and plain jane but that,s just me, here,s a couple examples i polled out of my collection. really like the OGH, there pretty cool So what,s your favorite TPG
I view TPG's differently than most others. They aren't an avenue for profitability to me. A TPG exists to protect my coin for future generations and render a professional judgment on the grade. That's all and nothing more to me.... And in that vein, I am an ICG guy simply due to the cost.
PCGS is my personal favorite but I have bought a small gold coin in a CAC holder too (yes I don't care it's not a real TPG I think their holder is nice ).
I had a brain fart here and completely forgot about CAC only holders would for sure put them in the same conversation as PCGS and NGC.