Turf War- Wahoo World. Despite the fact Wahoo World is fairly unique in terms of how big the map is and how there's multiple parts that move, it feels like just... the default Turf War map
Rainmaker- Hagglefish Market. I think part of this is because when I was putting together my gear abilities when I first started playing NTri, I had Hagglefish in mind when I was considering whether or not I should put enough Ink Saver (Sub) on to get two Fizzy Bombs.
Tower Control- Sturgeon Shipyard. Mind you I don't like Tower on Sturgeon, but that's just THE map I think of
Clam Blitz- Scorch Gorge. Again I don't like Clams on Scorch but it just feels like the default for me.
Splat Zones- MakoMart. I like the stacks so that's what I think of, also I just like MakoMart in general so it being the "default" map for something was bound to happen.
BONUS ANSWERS
Salmon Run- Sockeye Station. One of the easiest maps so naturally I play it more, so it feels default, even though my favorite is Gone Fission Hydroplant. I'm also biased because Sockeye was in rotation the first shift I ever played
Tricolor- Mincemeat. Not only one of my favorite Tricolor maps in general, but it's the one I feel plays the most like how Tricolor is supposed to feel, y'know?
Literally Any Of The Challenges- Hammerhead Bridge. Stop putting Hammerhead Bridge in Challenges, it sucks and appears too often.