SGC  =   Accurate , Value , Consistent ,  NO  Conflict of interest , and also I high resale prices realized in vintage products.             

                   BGS  =   Conflict of interest in several areas  one is their previous article they used to do about prices paid for graded cards and the obvious slanted bias against other companies and no mention in the negative light whatsoever of their own. Also the fact that they are buisness that was started on  PRICE GUIDES , possibility of  influencing their own prices ,  Also the fatc of purposely just grading cards harder just to do it and gain an undeserved reputation for supposedly accurate and supposedly tough grading , all that said for modern cards  90s to the present they do seem to have the most activity  in the market place. Also the fact that they also grade through the   BCCG  line. Which any experienced collector knows is just another way of getting more of their slabbed cards out there. Cheap and   INACCURATE in GRADING  even admitted by them , by their own standards.   Also they have   BVG wow  a third  grading alternative good grief old or new everything should be graded by the same standard  PERIOD.                               

  PSA  =  They were the ones  backed by  David  Hall  who started it all in both the  Sportscards and also  Coins    followed shortly       after by                                                                                                      SGC

  PSA  = In accurate  Grading  I have personally seen and have physically held in my hands  PSA graded  10 Gem Mint  Cards that were by plain eye sight visibly  off center  hence they should have been graded either  a   PSA  9   or    PSA  9  OC     OC =  Off center              Also the fact that you have to pay for every little thing and the fact that they are a publicly traded company on the  NASDAQ stock exchange  show they have only their own  and their own stockholders interest at heart.

  GAI  =  Although I have not had to much experience with this company or their card. What little I have dealt with them they seem to be  Ok. Below  SGC  standards but right up there with  decent grading and fairly unbiased , There one MAJOR  drawback is that there cards don't usually reach the prices realized by the other big name grading companies  I.E.   SGC ,  PSA , and  BGS.

 All other 3rd party  Grading  companies  =  PRO , WCG , FGS , SCD , GEM , WCCG  and so on. Are all out there just to soak up any money they can. These companies should absolutely not be used for the simple fact that once in those slab those cards will not get any real respect or merit which would be a shame if you were talking about a  high grade  1952  Topps  Mickey  Mantle and the difference of getting several to tens of thousands more for your card.

 My own personal choices in order.   All around and specifically vintage is   SGC , then   PSA , then  GAI , and dead last other than the suckers who are just blindly loyal to the  Beckett Brand name  BVG  which only gets high prices paid by a few collectors. Otherwise the high prices paid at the actual  Auction Houses are always for cards  GRADED  BY  SGC , PSA , or even   GAI.

  My own personal  choice for  modern cards first and foremost for Quality and accuracy always  is  SGC , followed by  BGS  B/C this  would be the one section of the card market where they do perform well, also the fact that they have good # of cards out there = decent trading volume , next up would  be  PSA , followed very shortly thereafter by  GAI.