My low-key favorite Luffy and Zoro moment is in chapter 22. It's after they defeat Buggy and join forces with Nami. They are just drifting on their dinghy and ask Nami for food. She wants to know how they survived for so long.
Also chapter 22 is in volume 3, which is one of my favorite covers because it's just Luffy and Zoro. I don't think Oda will ever gift us with something that wonderful again!