This meme from a few days ago sums up the situation quite nicely.
To find the answer to your question you will first need to answer another question: why are you grading in the first place?
If you’re grading for profit you’ll want to go with an established company. The general rule of thumb right now is:
- If you’re grading for a quick flip: go with CGC;
- If your card has a shot at a BGS Black Label: go with BGS;
- If you’re grading for a slower flip with a higher price tag: go with PSA.
If you have no intention of ever selling the card, go with whatever grading company you like.