We all have our favorite brands in every industry. Below is a short list of a few of mine. I own, or have used gear from every name on this list and trust them every time!
Cressi: great for snorkels, masks, and guns
Mares: Famous for fins, also make awesome guns
SpeargunReviews: Best insight into spearguns
ScubaPro: Great in the scuba arena, obviously. Love their masks
AB Biller: Guns guns guns!