Mayonnaise? Fucking delicious. Easily the best condiment. Goes great on nearly everything.
You know those combination sauces that Heinz released a while back that everyone dunked on, like "mayochup" and "mayocue"? Also delicious. Mayo mixed with ketchup is the best sauce for fries, and mayo mixed with barbecue is great on sandwiches.
Every downvote on this post increases my self-esteem.
I've said it before but it bears repeating - mayo is fat, salt and acid (and store bought often even has sugar). It is literally made of the things that make food taste good.