Lab grown. I'm curious how they replicate the flavors of animals. Animals usually get flavor from the food they consume. Lab grown meat doesn't eat. So do they add the flavoring chemicals to it? If so that could lead to some interesting things. Being able to full control the texture and flavor of the meat would mean replicating various meats. Or mixing their properties. You could have the texture of chicken breast but taste like beef. Then there's the ability to add flavoring without marinades. Imagine a slab of lab bacon that's "naturally" smoky. You have to marinate or inject to get flavors into the meat. Imagine being able to actually construct the meat with those flavors.

Seconding ancient extinct animals. I would imagine mammoth is pretty pungent and a grassy. Dinosaurs would be interesting too. I probably wouldn't try it but ancient giant bugs cooked like prawns or shellfish.