I like Allinsons brown bread or lidl sourdough. I can't do the normal square shaped white one really. It's under "meh" category. Go wild 😁 Most of mine are actually quite ok - helathy overall imo
You can have much fun with fillings!
My faves simples are
spring onion, crumbled feta, soft cheese, black pepper
Chicken, harissa, yogurt, tomato, lettuce
Beef slices, horseradish mixed with bit of quark, rocket or similar leaves, tomato, onion (unless at work...), bit of mustard
Not so "simple" sandwich
Rachel - pastrami (can use any beef really tbh), sauerkraut, mustard, strong flavour, sliced cheese, pickle
Wraps
Beef, labneh mixed with chopped magdoush, rocket or spinach leaves, olives, tomato,
Air fried crispy chicken, lettuce, onion (unless at work, can use spring onion instead), pickle, tomato sriracha yogurt sauce
And then ton of weird combos of what's in the house...
Chaotic salads are proper fun too in warmer months especially!