@angelBraids - I can help you out, as I happen to have an entire cookbook dedicated to this one dish.
The absolutely easiest way to add variety is to change the cheese used. Many people go for cheddar because it's familiar, easy to work with, and often the cheapest type available. That's not always a bad thing, but there are so many more strong and versatile cheeses out there that work well too.
Here's my potatoes au gratin gruyere recipe. It's unbelievably simple with only four ingredients: 3 llbs of peeled potatoes, cut into 1/8-inch thick rounds; 1.5 cups crème fraîche; 1.5 cups (or 6 ounces) of grated Gruyère cheese & 2 tablespoons of fresh parsley, chopped.
Here's the method:
Heat the oven to 400°F. While waiting you can butter a good sized glass baking dish. I use one around 13 x 8 or 9. It should be around two inches deep too.
Slightly overlap half the potatoes on the bottom of the dish and add some salt/pepper. Put half of the cheese and the creme fraiche on top, repeat - so the grated cheese is the final addition.
After 30 minutes you need to reduce the temperature to
350°F. It will then take around another half hour or so, though you need to check the potatoes to make sure they are cooked through. (The dish should be uncovered throughout.)
When it's done leave it to stand for a few minutes and add the parsley just before serving.