Is several guys here with a problem to understand the title or just want to say what they like?
The question isn't what is the best first boss fight, the question is the best OPENING boss fight. Most of what people said isn't fight on the opening of the game, that is totally not common.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
Azzanation: "PS5 wouldn't sold out at launch without scalpers."