In a world filled with immensely enjoyable sandwiches, it's pretty foolish to attempt to crown any particular variety as the best. Well, don't ever let it be said that we here at Scene aren't fools.
The BLT — not even by a little bit — is the World's Greatest Sandwich. In terms of form and function, taste and texture, simplicity and objective, this unassuming stack of four modest ingredients (and one pale condiment) delivers more pleasure per square inch than most solid foods. It is perfect in its equilibrium: ratio of meat to bread and vedge; balance of sweet and salty; juxtaposition of creamy and crunchy. It has bacon, which already gives it a leg up on most earthly things, let alone sandwiches. But without the supporting cast of cool, crisp lettuce, sweet and juicy tomatoes, and bright and tangy mayonnaise, that bacon would never rise to its porky potential.
We don't often think of sandwiches as seasonal foodstuffs, but don't even bother to make, order or attempt to enjoy a BLT at any time of the year other than the pinnacle of summer. Bacon and lettuce might be year 'round staples, but perfectly ripe tomatoes are not. And when it comes to the mayo, it's best to stick with homemade, Duke's or Hellman's. Miracle Whip is murder on a BLT. As for the bread, keep it thin, toasted or grilled, so as not to get too much in the way of the real stars of the World's Greatest Sandwich.
I'll await your angry replies on the topic, but just know that you are wrong.
More on the sandwich:
A Cleveland Journey Through Our Favorite Things Between Two Slices of Bread