/What can I add to my hash brown potatoes (besides onions) to make them more exciting.?

Paprika, white pepper, powdered onion. Melt a tiny bit of cheese

Minced cooked bacon or ham.

Minced sautéed green pepper.

Minced salami.

Cheese, red pepper flakes, garlic, bacon fat and/or bacon, parsley, chives, a fried egg. You could do them Indian style with ginger, garlic, cumin, cayenne, coriander, and turmeric.

Shredded chicken

Cheese, sweetcorn, scallions, chopped tomatoes/bell pepper, chorizo, herbs, spices, chopped ham/bacon, eggs[scrambled],

Finely minced red, yellow or orange bell peppers.

Bell peppers and bacon

red bell pepper, chopped pimentos , personally I like spicey so red pepper flakes

Chopped chilis.

Fresh diced jalapeno.