Can any doc tell me what's the best vitamin/supplement company out there?

Many good ones: There are many excellent, high quality supplement companies. Each physician probably has his or her own favorites. When considering individual supplements, consider using consumerlabs.com which conducts quality testing on products from a large number of companies.

Dr Maes and another doctor agreed

Very subjective: Some people would say the best companies are the ones that sell the most or make the most amount of profit. Most multivitamins do not contain complete vitamins, but mass-produced parts of vitamins. Some vitamins are complex mixtures, and large drug companies only add parts. Like ascorbic acid substituted for Vit C. There are a few makers of complete vitamins, and you should look for them.