So there's several ways to cycle an aquarium but what's the best way, specifically for a marine aquarium? Fishless cycling of course, but should you use pure ammonia, fish flakes, a dead shrimp, or some other method? I've heard of some kind of bacteria in a bottle you can use but I think that's controversial (possibly doesn't really work?) and I've even heard of using human urine but somehow I feel that's not the best of methods...

I like the dead shrimp method. It's easy, it's natural and there's no way it can go wrong really (except you should put the shrimp in pantyhose, to keep the decomposed pieces contained so you can remove them). Unlike, say, adding too much ammonia. I think it's faster than using fish flakes too.