I use cajun seasoning–I love Bojangle’s fries with their special seasoning, but they never put enough on, so I have to put more on but the chain on the little seasoning shaker is never long enough.
I second the poutine suggestion, or how about just gravy? They also have interesting combos at New York Fries, cheese, chili, sour cream, onions, tomatoes, peppers, etc.
I second sour cream, and lots of it. MMMMM.
Ranch dressing is sooo good on fries. Actually, it’s good on mashed potatoes too (my Dad taught me that).
When I go to Subway I always ask for extra pickles and have people making comments about being pregnant. Nope, I’ve always gotten my sub with extra pickles. Before, during and after my pregnancy.
Thai peanut sauce.
You know, it’s funny. I love Thai peanut sauce on all sorts of things, from Totino’s pizza rolls to cheese tots. But not on french fries. Weird, huh?
I love to dip french fries in salsa. I’ve never been very keen on ketchup. Too bland for my taste.
Ranch + Ketchup + pepper
or any combination thereof.
Well, lately I’m on a Thai curry kick and I have found one of my favorite alternative uses for Thai Red Curry Paste. I cut up a couple of potatoes into giant wedge frys and toss them in a slurry of a tablespoon of Thai Red Curry Paste dissolved in a teaspoon or two of vegetable oil then bake them for about an hour at 375F. They are tasty alone but sometimes I dip them in homemade hot sauce.
I imagine Tabasco Chipotle sauce might be a good fry dipper.
Cheese curds and gravy! Er, yeah, poutine, as someone mentioned above.
But try different gravies: turkey gravy, chicken gravy, beef gravy. I’m partial to turkey gravy, myself.
And try different curds!
And sometimes I’d slather that mess in ketch… oh yeah. Nevermind. 
mustard
The other day i tried Arby’s Horsey Sauce on my fries. Pretty good.
Tartar sauce.
You can thank me later.
Salt and vinegar (malt or white both work) is the best accompaniment to fries, but when i was a kid I liked to have my fries with HP sauce. Give it a try!
Vinegar with ketchup can be good too.
Replace ketchup?
HERESY!!!
If it’s too sweet, you’ve got the wrong ketchup.
Peri-peri sauce.
One more idea: If you ever go to Roy Rogers, mix 1/3 horseradish sauce with 2/3 ketchup. Tremendous! I’m up to a 50/50 mix myself.
Given the choice, I eat just about anything you’d normally have ketchup with, with BBQ sauce instead.
My G/F prefers her fries with gravy…