Glorious ketchup master race.
I can't stand the other two
If you take 2/3 ketchup and 1/3 mayo and mix it, and dip your chicken fingers or fries into it.. Delicious.
I like ketchup and mayo equally, though I prefer mayo with sandwiches, and ketchup for fries and hashbrowns. I won't use mustard by itself. In fact, I have never used mustard when making something at home. I've only ever had mustard on a McDonald's cheese burger because it comes with it (and eating McD's is a rarity).
Mustard because out of the 3 it's the only one that can have a large range of flavours and ingredients.
ughhhh, I can't stand mayo on many things. I only have it on basic sandwiches, probably since they've always been on them when I was a kid. I do like that it keeps the sandwich from being dry. And even then, it's the thinest of layers. I can not fathom running my finger along the side of my sandwich, pick up some mayo, and then eat it straight up (gag). That being said, I also have mustard on almost all types of sandwiches, be it yellow, brown or spicy. I do like almost all types of mustard though. Ketchup replaces every other bread-meat combo though: hot dogs, burgers and...well, don't know what else. Of course, mustard is the main attraction.
But there's also BBQ sauce, and that's on a whole different field. I think BBQ sauce might be too spread out though, there's so many types, like this one time, at the Hard Rock Cafe in SF, I had this burger thing, I think it was the south carolina burger or something, but it had the most amazing mustard base BBQ sauce /drool
Definitely ketchup over mayo, even though I do really like mayo. But I don't like mustard all that much.
But really, when it comes down to it, just put tobasco sauce on all the things.
I'm bad, and that's good. I will never be good and that's not bad. There's no one I'd rather be, than me.
A nice stone ground mustard over roast beef YUUUUUM! But they all have a place.