White wine, most definitely. Generally speaking, fish, being a "lighter" texture than many meats (such as steak), would be complemented by a lighter wine, i.e., a white. (Red wine, being generally "heavier" than white, goes better with red meat.)
Custom has it that you drink white wine with fish. However, it somewhat depends on the fish, if it is a strong flavoured variety, red wine would be OK with it, whereas a mild flavoured fish would do better with white wine.
I love red wine with any and all food, however white is the custom.