I personally would kill for Honey Glazed Yorkshire Ham nestling on a bed of crisp Iceberg lettuce and fresh sliced beefsteak tomato, with just a smidge of mayo.
The bread would be Granary brown and the butter, Anchor (salted)
Wrong forum buddy 
A Hy Sofer roast beef on Mont Pleasant Bakery rye bread with russian dressing and a half-sour pickle. Heaven!
Alas, Hy Sofer has been out of business for decades, but there’s a good deli nearby that comes close.
BLT with home grown summer 'maters. Toasted Reuben is in a distant second, but still far ahead of anything else.
Vegemite with margarine on bland supermarket white sliced bread.
I’m moving this to IMHO.
And my favorite sandwich varies…but generally I like some sort of salted meat with Swiss cheese on rye, with mustard.
Boy do you know your butties mate;)
The chicken salad club from Perly’s Deli.
What a wonderful insightful question. This is the sort of world-shattering quiz I love!
Hmmm … so many, so many! The ol’ BLT with home-grown veggies from my parents garden and just a bit of Feta cheese on freshly-baked french bread … mmmmmmmmmmmmmm… :homer:
Hm, forgot to answer the question…
Smoked turkey, bacon, light mustard and a slice of cheddar cheese either as a panini or inbetween sliced brown bread.
At the moment, mild to medium cheddar cheese (REAL cheddar, not the pre-wrapped singles) on pumpernickel rye bread with just the slightest layer of butter on the bread to make it a bit moist.
Thick oozy grilled cheese, where the bread is just barely golden, and the cheese nice and hot. If there’s a bowl nearby filled with thick chicken soup to dip it in, all the better!
Thick slabs of lox Salmon, cream cheese, purple onions and lots of capers on fresh rye bread.
And for the record, the best one I ever had was in Portland, Oregon at a little place called Rosies. sigh
Just plain old peanut butter on some soft white bread.
Yes, I could go for that. But it would have to be Marmite. None of these pale imitations
I wish I hadn’t started this thread 'cos looking through this magnificent selection has made me hungry enough to eat a dead skunk, with or without mustard.
A rueben from Shapiro’s deli. Mmmm…9 a.m. and craving corned beef.
Yes, me too Spogga 
I’ve never tried Vegemite/Marmite before and woud actually love to try it…I’ve heard it tastes kinda yeasty. Methinks it may go well with beer!?
As noted in other threads, gotta say Primanti’s.
Without a doubt the Cuban Medianoche .