Fries first, always. They get colder faster, and aren’t nearly as good as when they’re hot. The burger can wait.
Like others here.
Fries first, especially if they’re skinny and prone to rapid cooling. Then I eat the lettuce and tomato, if applicable. That leaves me with an easily-handled burger that won’t slither apart when I bite into it.
If made perfectly and fresh, fries first; a cold burger is still good, but cold fries are an abomination.
Apparently, I misunderstood the question: I thought it was, “Do you start with the burger, or the fries?”. Apparently, it’s more like, “How much of whatever it is you start eating first do you eat before you eat the other one?”.
I always start with the burger, but usually I switch back and forth enough so I finish both at just about the same time.
is this the hat that’s in/near orange county ?
edit:wow I never knew there was more than one …my relatives rave about this place … I’ve never been there I wonder if there’s more than one …and you’re right my uncle who eats there when his security patrol route takes him near one says never order the fries unless there’s 2 people eating them … he’s even asked for a half order and says they’re still too much …
I’m taking note of all you ‘burger first-ers.’
Your french fries are at some risk 
With any meal, I pick the one food that’s horrible when it achieves room temperature and eat that first.
I absolutely love hot french fries. Utterly hate cold ones.
Same here. Taste a few fries, then the burger, then the rest of the fries.
Burger first, completely, then fries. Always.
In fact, no matter what I’m eating, unless it’s all mixed together, I’ll always eat the protein first, and only then the side dishes, one after the other. I don’t know why.
actually 90 percent of the time my fries are covered in some type of meat ,chili or cheese or a combo therein so …
I alternate a bite of burger with a few fries, trying to pace it so that they both disappear at about the same time. If the final bite isn’t fries, though, I feel like I’ve messed up a bit.
I don’t find the fry degradation in the time it takes me to eat significant enough to worry about.
Another reason for fries first that depends on the burger joint: giving it an extra minute for the meat juice and fat to reabsorb into the patty or into the bun prevents a squirty mess when you bite into the burger. Much like resting a piece of grilled meat. But yeah, mostly because if my fries cool/become limp, they are going to be left behind.
Now, a partial exception, if you have having really low end fast food burger/fries (which in my case, pre-covid, was about one every other year or so doing a loooooong drive where McD or the like was the ONLY place of note to get something hot) with American ‘Cheese’ ( 
). I find that if it cools it become even more disgusting, so I’ll scarf the burger more quickly. And why the cheese if I dislike it? Because McD gray-toad burgers needs as much concealment as possible. But we digress.
like that except I like the cheese a little more melted now if they added carne asaada …
To me, what McD’s needs is the sauce. I get Mac Sauce on all the burgers.
They are the only fast food fry around here that keep their fry oil completely separate from the breaded stuff, and I’m allergic, so those are the only fast food fries I’ve eaten in ages. I seem to remember some other fries staying good longer.
If you eat the burger first, then the fries are going to be sitting for the amount of time it takes to eat the burger. And especially for really good fries, even that short amount of time can make a significant difference.
Of course, the burger will also degrade with time. You don’t want to just set it aside and pick it back up a couple of hours later. But burgers degrade much more slowly than fries.
For me, in more detail, it’s a couple of fries as soon as I get them, some sips of beverage, and then alternating bites of burger and fries. Depending on the place, there are often way too many fries to eat, so they end up getting discarded.
The vast majority of fries are mediocre. And, in fact, I once ran a poll declaring that McDonald’s fries are the absolutely worst fries of any kind—a lot of people had the bad taste to disagree with that.
I like fries that are medium cut, not dry-and-cardboard-like (like McDonald’s) nor soft and greasy (like U.K. chipper chips). I like an average thickness, even throughout, with a nice crisp outside and a fluffy inside.
Right now, my favorite fries are from Shake Shack. I think that wavy cut helps achieve the perfect variations in texture. Although I go to Five Guys more often, because it’s more convenient, I find Shake Shack’s fries to be better (although I prefer Five Guys’ burgers).
I usually put some ketchup and salt on fries, but I’m always in search of fries that need no additional seasoning. Where malt vinegar is available, I might use some of that—alternating with ketchup. (I’m a dipper, not a douser)
I also believe that ketchup only goes with certain foods—burgers, dogs, fries. Definitely never on scrambled or fried eggs (disgusting!) or potato chips (crisps) or pizza (heathen!). I make my French toast savory (not sweetness at all) and like ketchup/hot sauce with that.
Yeah, with me, nothing lasts long enough to degrade.
Where I live, the fries “cooling off” still usually means they are at well over 100ºF (38ºC) so I am free to eat my burger and then consume the salt & oil calories (two of humanity’s favorite food groups!).
Ditto.