Nah, definitely a hot turkey sandwich.
My fav hot sandwich has got to be pastrami on sourdough. Grilled, with provolone and swiss, a fried egg, and sliced tomatoes. Pickle on the side. To make this one right, instead of butter, you put mayo on the side of the bread you are going to grill. Browns up almost like french toast.
Cold:
Fresh, homemade chicken salad on rye. Mmmmm-MMM!
Tuna, olive, lettuce, tomato, HB egg, onion, olive oil and vinegar on a crusty baguette. Good picnic sandwich - with a cold glass of rose wine.
Hot:
Carolina pulled-pork sandwich on a white burger bun with a bit of BBQ sauce. Bottle of amber ale on the side.
Classic French roast beef dip on a soft roll with extra au jus for dipping.
Hot sandwich:
Cheesesteak is good. So is thinly-sliced roast beef served with au jus to dip it in. French Dip! The name eluded me at first.
Cold sandwich:
Leftover turkey, stuffing and homemade cranberry sauce between two slices of potato bread. Sometimes I make that meal just for the sandwiches the next day.
I also love leftover meatloaf slathered in Miracle Whip between potato bread.
Oh, yes. 
Sheri
Hot:
Cajun meatloaf with tomato, lettuce and mayo on a sesame seed deli roll.
Cold:
Ham, hard salami, cappricola, provolone, tomato, lettuce, pickled banana pepper rings, oil, vinegar, oregano, and a dash of salt on a soft hoagie roll. (The salt and oregano are on the tomato slices.)
Cold runner-up: PB & J on white with a glass of milk to wash it down.
Peanut butter on toasted wheat.
Toasted rueben, light on the sauerkraut and with mustard.
The Boston Market Carver Club minus the tomato slices.
Hot: The grilled-cheese sandwich on sourdough bread encrusted with parmesan cheese. I love cheese. Cheese is beautiful. This sandwich is best if you use cheddar, monterey jack, and gouda cheeses inna middle. droooooooool Oh yum. Oh yum yum yum …
Cold: Thinly-sliced chicken breast, lettuce, tomato, bacon (well okay, that part I like warm), and swiss or mozzarella cheese on a toasted garlic bagel with muchly-mayo. Mmmmmmmmmm … anything on bagels is good!
here is another take on the same topic wherein I detail the Perfect Sandwich :
http://boards.straightdope.com/sdmb/showthread.php?threadid=61324
Cobb sandwiches, my favorite incarnation having blue cheese, pepper bacon, turkey, garlic mayonnaise, avocado, lettuce, and onion on toasted sourdough. I would commit horrific crimes for a good Cobb sandwich. When I can’t get one of those, though, I like hard salami and butter. Note that what passes for salami in the United States is not at all acceptable, except perhaps Hebrew National. German salami is best, I think. I don’t really go for hot sandwiches.
Sandwiches: the best thing ever to come from a gambling addiction.
A cheesesteak, or toast with tomato and Miracle Whip.
One of my all time favorite sandwiches:
[li] Dark Rye (nothing else is the same)[/li]
[li] Rare Roast Beef[/li]
[li] White Meat Turkey[/li]
[li] American or Cheddar Cheese[/li]
[li] Lettuce[/li]
[li] Tomato[/li]
[li] Onion (light)[/li]
[li] Horseradish (light)[/li]
[li] Heavy Best Foods Mayo[/li]
[li] Heavy Mustard[/li]
Pepperoncinis and some Miss Vicky’s Jalapeño potato chips on the side. We’re talking major taste bud orgasm here. In a pinch, you can use the marbled rye, but light rye and other breads just don’t cut it. Same goes for the cheese, stick to the recipe. Very rare roast beef is preferable to overcooked.
Don’t think me weird for this, but I absolutely LOVE peanut butter and grey poupon sandwiches. My boyfriend thinks its nasty, but he eats PB & ketchup sandwiches
Peanut butter, honey, and bananas. On whole wheat. I can’t believe no one else has mentioned this yet. What kind of savages are you? 
Bread must be rye, slightly toasted and still warm. Cheese must be two thick slices of sharp Cheddar, one on each slice. Pile tomato, lettuce, onion and mustard at will. Spices are optional - I put a touch of garlic and a pinch of pepper to spice it. Put it on a plate, and send it down the gastrointestinal Autobahn with love. Wash down with cold, unsweetened tea and I’m in gustatory heaven.
Toasted Rye Bread
Grilled Portobello Mushrooms
Avacado
Roma Tomatoes
Butter Lettuce
Sauce made of: Plain yougurt, dill, lemon juice, tarragon, paprika.
yum!
Please allow me to mention the rather obvious fact that you’re both quite insane.
The Thunder and Lightening sandwich.
White bread, clotted cream and golden syrup (oh and about a kazillion calories).
No really - trust me, it’s the finest invention in the known universe.
Hot Italian Beef -
1-Yellow, 1-Red and 1 Green Bell pepper
1- White Onion
1- Jalapeno Pepper
1- Can Campells French onion soup
1-Pound sliced roast beef from the deli.
Swiss Cheese
Hogi rolls
Slice onion and bell peppers into strips. Dice or slice the jalapeno.
Sauté these veggies in large skillet. I think olive oil works best.
Add Onion soup to the veggies in the skillet. You could substitute beef broth. If you want it sloppy, use one of both.
Take the wad-o-meat and slice it into 6-10 chunks. Add the meat to the skillet. Stir, simmer, stir, simmer. At least 10 minutes.
Slop concoction over hogi roll and melt cheese on top.
Heaven. Makes great leftovers too. Drives my co-workers crazy.
White or light rye bread, rare roast beef, dab of mayo, tons of salt. Perfect!
In summer when the tomatoes here are good, I sometimes toast whole wheat, butter it, then sprinkle hot pepper, garlic powder, and oregano, then sliced tomatoes, then shredded mozarella & broil it. Pizza reinvented.
I eat cold sammiches almost every day, usually on whole wheat.
Today I had:
mayo
sliced cheddar
onions
tomato
lettuce
yesterday
mayo
sliced avocado
tomato
lettuce
day before
egg salad w/mayo
day before
peanut butter
sliced celery
last week:
tuna salad (made w/ mayo, chopped onions & celery & a little dried basil & coriander)
If I’m in France I sometimes use a baguette to eat
tuna (their canned tuna is so much better than American tuna)
mayo (also better) Actually, almost all the food’s better.
tomatoes
lettuce
or
smoked salmon
boursin
onions
tomato
lettuce
or hell,
just french cheese & baguette