What makes an effective loaded tater? Onions appreciated.
 

It's all about the dairy: Cheese and sour cream!!

I'm a cheddar and bacon girl myself. I mean that's what I like on my skins, not that I'm actually made of cheddar and bacon. But if I were I'd be yummy.

Don't forget green onions or chives! Just not both... they compete in your mouth too much. Fresh grated Cheddar, not too sharp. Crumbled bacon should be the dominant taste. The rest should compliment the bacon and the potato should provide the vehicle and filler flavors only.

Roast the potatoes with olive oil, crushed rosemary, a little garlic and a pinch of salt. Yummy!

Now, are we talking potato skins?
Or baked potatoes (what we call jacket potatoes here - whole large potatoes baked in the oven and eaten split open with toppings in the middle)?

For me the best jacket potato came from Croques in leicester. They were properly baked until the skins were crisp and filled with (proper spicy) chilli, grated cheese and sour cream. They were too expensive to have other than a payday treat, and too filling to eat if you'd already had breakfast - three meals in one!

Classic make-myself would be baked beans - on first! - and grated cheese.
Anyone who puts the cheese on first is a heathen.
I have very strict views on potato toppins. Cheese and coleslaw for example sends you to Tartarus.

Baked potato skins.... well. They're usually a mite greasy.
Too filling for a starter or a side, too samey for a main.
But hey, if you're cooking then I'm eating. Cheese & bacon is fine, thanks.

It is all about the bacon. You can pretty much put anything else under the bacon crumbles. Cheese and broccoli. Gotta have your RDA of cruciferous vegetables!

My understanding is that the traditional "loaded" is cheese, bacon, and sour cream, but since I seriously dislike sour cream, I've never had a traditional loaded potato.

I like twice baked potatoes.

baked, sliced in half lengthwise, scooped out. the potato is mashed and mixed with sourcream, feta cheese, cream cheese, butter, cheddar, bacon bitz maybe... it's variable. skins are refilled, and rebaked.

delicious!

The local bakery I didn't work at in Leicester did their jacket potatoes in a similar way.
They scooped, mixed and refilled. They didn't rebake, just kept warm from what I remember.
And not will all those toppings eother, just butter and seasoning, but it was piped back in. A very odd experience for me, especially as I never use salt & pepper on my potatoes.

Bingo! Perfection on the taste buds.