What is the best sammich you ever had?

I bought an ordinary kind of sammich from a sidewalk vendor one time but what made it so special in tastiness was the kind of spice they used in it. I went back and asked what the spice was but they would not tell me.

I'm partial to Reuben and hot pastrami sandwiches.

Kosher pastrami, beef tongue, half-sour pickles, and cole slaw (or mustard or Russian dressing) on rye.

A corned beef Reuben from Katz's deli in lower Manhattan, It was really expensive but so worth it. 

Grilled portabella with goat cheese and walnuts. 

Nothing stands out, I don’t really care for sandwiches. 

every time I eat a banh mi it’s the best sandwich I ever had