I had horse meat sausage/cold cuts in Belgium along side more typical pork varieties. The horse was not bad, but I preferred the pork. Alligator does taste a bit like rather chewy chicken. It can be a bit tough if not prepared properly. It tends to take on the flavor of whatever you season it it with. Frog legs tasted like VERY mildly fishy chicken, but with a finer texture maybe like quail. As for tuna, i cannot say one way or another as to the aging of bluefin, but the one thing about bluefin is that it travels well so you can age it. The other tunas, not so much. Fresh yellowfin tastes very good raw even if it is not "sashimi" grade. I am told that the lower grade stuff with degrade faster. Our most common true tuna here in Florida is the blackfin which tends to top out in the 35 pound range and is VERY good as long as you eat it within say 72 hours even with freezing. It starts to degrade very quickly and I suspect that is why it is not a commercially exploited species. It is the only true tuna that is not heavily protected and regulated in the US. If you go places like Key West and especially around Cancun during the right time of the year, they are like a plague upon the ocean and very easy to catch as they are aggressive feeders like their larger brethren.
As for me, i want to try Kobe beef, moose and goose. I would also like to try some more exotic game dishes, especially stuff like eland. I have had nilgai and it was damn good, like elk. I have also eaten sea turtle in Cuba but it was prepared as a palomilla steak heavily soaked in mojo criollo so it didn't really taste much different than the beef version of that dish. I should also endeavor to try more ugly fish. Some of the fish that you would NEVER want your dinner guests or customers to see whole are some of the best tasting, like hogfish and tilefish. Sheepshead are ugly little spuds too and damn hard to clean especially considering the paltry amount of meat you get, but they are yummy.
I love that white gravy... Id eat it with everything!