You can add me to the ghee list. As other have pointed out: easy to make, tastes great, and doesn't spoil.

Depends what I'm going to be eating, but I like ghee for most frying.  I bring a small amount of olive oil for cous cous and dried hummus (if those are on the menu) and canola oil if I need something else.  The only problem with ghee is the residue, but a decent dish soap and warm water does a great job.  Sometimes I will bring a few paper towels to wipe out ghee infused dishes before cleaning, that seems to help (and boy do those towels burn well...).

Canola oil and squeeze Parkay marjorine. Use 50/50 when frying fish!

olive oil-the cheap stuff.

I use peanut oil packed in recycled plastic soda or water bottles for frying fish. For almost everything else the versatile squeeze Parkay.

I used the heart-smart spray stuff (Smart Choice, I think) on one solo trip to fry up some yellow perch. I first tried this stuff when I got some for my dad (he had to spend some time on a restricted diet). It doesn't need refrigeration (?) and really tasted good.

Normally I don't pack butter or oils on solo trips...

-aj

I used to use just a good olive oil but have switched to a combo oil with olive oil/sunflower mix.
This has a higher "smoking" temp than Olive oil but is still good for you.
I also use the Ghee, which I didn't know was the Indian name for clarified butter until I Googled it
Clarified butter doesn't need refrigeration at all and adds great flavor as well as the ability to cook at a higher heat without smoking and burning.
EASY to make and worth a look if you like butter in your dishes

I pack butter in a wide mouth one or two cup plastic bottle, a recycled peanut butter jar for example.  I pack olive oil in a small plastic water bottle with pull up nipple top, also pack cooking oil this way.  Recycled water bottles seem to be the least likely to leak from the cap.  I sometimes bring a little solid shortening (like Crisco) packed as I do the butter.  It all depends on what I think I will be cooking.  All of these are slid into additional plastic zip lock bag to prevent any leaking into the pack.  Butter is the most likely to spoil or melt on a two week summer trip; but I have never had butter actually go bad, it has melted tho.
Lard or shortening is the least likely to burn when frying things as it has a higher temperature tolerance.  Olive oil and butter have the lowest temp tolerance.

I use peanut oil or bacon grease for fish followed by the spray butter stuff for the final brown. I've used the squeeze butter in the past for stuff like cheesecake, english muffins... but I think I'll go w/ the spray from now on. It had a bit more flavor and was more convenient plus the pump/cap fit perfectly on the bottle I use for repackaging. I don't deep fry anything so my oil bottle holds less than an oz and a half.

canpaddle - I don't think I could keep butter from burning to actually fry something in it. Do your fried potatoes start off raw or cooked?

Vegetable Oil for most frying ... Olive oil, when called for (e.g., Pesto, Couscous).

dd