I’m so sorry you are tied to a chair and being forced to watch TV. No wonder you’re grumpy and incoherent.
As to grilled cheese sandwiches, they need to have dill pickle slices inserted after cooking. No further condimentation is required. But tomato soup is a nice accompaniment.
Tomato jam or sundried tomato tapenade/spread goes great on grilled cheese sandwiches, but both are hard to find outside of Amazon.
I blinked at just the wrong moment and read that as “tomato poop” the first time. Oops. 
And yeah, dunking in the soup is a decent alternative to ketchup. In fact I suspect as a kid I tried ketchup as a substitute once when the traditional soup wasn’t on offer. And found ketchup works real well too.
You know, tomato spread on grilled bread with melted cheese sounds kind of like something you could get New York style or Chicago style…
Yeah, pickles go good. Mustard is good, too, but I like dipping in ketchup. There is something about cheese and ketchup I like, which is a condiment I typically use very sparingly. Sliced tomatoes in grilled cheese I don’t like. Nothing appetizing to me about a warmed slice of tomato in a sandwich. Otherwise, I love tomatoes on cold sandwiches. Even with burgers I generally don’t prefer tomatoes unless they’re reasonably cool. Like on a McDLT! 
Trader Joe’s and Sprouts both carry sundried tomato tapenade. But yeah, some benighted backwaters don’t have such vendors of Wonderfulness.
Sorry you had to find out this way. Your dad and I were planning on having The Talk with you, but ain’t it funny how time slips away. 
My bold.
A fresh and badly needed new word: condimentation. 
Pickles with a grilled cheese sandwich are okay, but on the side. Dill (whole or slices) or – better – sweet gherkins.
I will go on record as saying that thinly sliced tomato is also okay on (that is, inside) a grilled cheese sandwich.
Ha!
I understood that reference.
The only use for sweet pickles or relish made from same is to ballast your trash cans so they don’t blow away. So there! 
I miss those. If they still had them, I’d forgo the BOGO menu on my rare visits.
Ah yes, I concur. I’d forgotten about that acceptable variant.
Cooper Sharp (a type of American cheese) is the ideal cheese for cheesesteaks. My nephew (a culinary school trained Philly native chef) turned me onto it years ago. It takes steak sandwiches to the next level.
My feelings exactly. I never eat pickle relish because it’s made with sweet pickles (I mistyped “ickle” — appropriate). When I was a kid I didn’t know why I didn’t like it. I later found it.
Does anyone know of an easily available sour/dill/sharp pickle relish??? I usually chop up garlicky dill pickles if I want a relish made of pickles.
I’ve got a pretty good recipe for dill chips if you want it. But I’m one of “those people” who like sweet relish.
You might like the Reuben rolls at my local german restaurant, Mader’s (serving german dishes for over 120 years). They make a pretty good Reuben Roll: Corned Beef, Sauerkraut and Swiss cheese inside a wonton wrap, with crispy spinach and Dusseldorf mustard sauce. Try 'em if you’re in Milwaukee.
At my place, we’ve been known to add pepperoni to the inside (I favor mozzarella for grilled cheese), and add Parmesan to the outside of the sandwich prior to grilling.
I do agree that sauces or dips just seem wrong.
I have a bottle of Heinz brand dill relish in my fridge (I hate sweet pickles and derivatives thereof too). Pretty sure that can be had at most good-size grocery stores, or on Amazon.
I have both a jar of dill and a jar of sweet Vlasic-brand relish at home. I don’t ever remember it being difficult to find around here. I typically use dill, but my wife and kids like the sweet, so I’ll use that for some stuff. I see the Heinz squeeze bottles around, too.
I stand proudly and loyally by my sweet gherkins. 
Not my local TJ’s. They have sliced sundried tomatoes. Also good.
Thanks all!
Aw, @ThelmaLou, I already knew you were a sweetie. 