This is my favorite marinade:

1 c soy sauce
1 c orange juice
1/3 c sugar or honey
2 cloves (or more) minced garlic
2 tbl (or more) minced ginger
2 tbl rice vinegar
2 tbl lime juice (lemon juice will do in a pinch)
pinch red pepper flake
4-5 twists of fresh ground black pepper

Marinade fish for no more than 20 minutes in 2/3 of marinade, reduce remaining 1/3 on stove for sauce at the table. BBQ fish, serve with sauce.