As a kid, my Mom only ever kept Miracle Whip on hand so I thought I hated mayonnaise. on occasion, I would go to other people's houses and wonder why the mayonnaise tasted so much better there. I hate Miracle Whip!
Fries + mayonnaise = yum
For grilled cheese (when I ate it), I would only use butter or margarine. Mayo on grilled cheese would just seem wrong!
Now, I use an eggless mayonnaise called Vegenaise, which is very close in taste to Hellman's. Vegenaise actually tastes so much like mayonnaise, I almost think restaurants could replace their mayo with it and nobody would notice. My guess is that it would not be cost-effective though, which is too bad.