What's the main allure for you?

The burgers, for sure. I've never been a fan of their spongy fries.

I'd be happy to eat elsewhere as well, but there aren't a lot of options at midnight.

For some reason I don't really understand, while I can't stand McDonalds in general, their fries are better than any of the "fast casual" places like Shake Shack, In-n-Out, etc. that I've encountered.

McD partially fries and freezes their fries before fully frying them. [1] That probably makes them more crispy and tastier to many (myself included). In-N-Out uses fresh potatoes, which means no fry-freeze-fry.

Five Guys has very crispy and tasty fries — especially the cajun style — that are not double fried. [2]

1: https://www.foxnews.com/food-drink/this-is-how-mcdonalds-mak...

2: https://www.delish.com/uk/food-news/a37315383/how-five-guys-...

I admit I don't remember Five Guys fries as anything exceptional but maybe I haven't ever had them. Admittedly I find Five Guys pretty overrated and expensive generally so I eat them even more rarely than burger places generally.

The burgers are overpriced compared to In-N-Out, but the lines are much shorter as a result. Fries aren't cheap, but 90% of the time a 'small' fries at Five Guys is bigger than a large anywhere else.

I always order fries "well-done" at In-N-Out now.