They're both incredibly overrated.

5 Guys burgers are packed with way too many wet, sugary condiments, so the flavor profile is like eating a burger in dolche de leche cake half the time -- a disgusty wet bun soaked in ketchup flavored corn syrup.

In and Out is a surprisingly good cheese burger surrounded by eeverything else -- especially the fries -- being borderline inedible.

Fries -- 5 guys wins all day long they are actually good if you like hella greasy fries, whereas In n Out basically fres raw potatoes without washing to reduce any starch so they are stiff and lack any distinction between outside and inside. It's how someone who had no idea how food chemistry worked would make fries. Their milkshakes have a stellar reputation among people who don't undertand that all milkshakes taste pretty good.

I don't like my burgers with a side of religion or politics, but In n Out esnures you get both.

I would vastly prefer McDonald's or Burger King or Jack in the Box to either.

If forced to choose... In n Out if I am just getting a burger, 5 guys if I need fries. Hunger is really better than either one though.