I've had shark twice in my life. Thresher tastes pretty good, but the black tip I had some years ago was just wrong. It smelled mildly of ammonia and had a strange metallic taste to it.
Caviar not really a meat per se, but fuck it is just seawater in little protein capsules. I fail to understand the appeal.
Worst of all is tripe. I HATE tripe. No amount of spice or proper preparation will ever make it taste of anything except vomit. Menudo is an exercise in futility if you ask me.
In the deli it has to be head cheese hands down. Nothing quite opens the appetite quite like and overspiced, cold, gelatinous loaf of meat and gristle salvaged from God-knows-where.