I really enjoy they're outfits and look forward to what they're wearing every arc, but u stole my idea for making this thread but oh well.
Luffy- Well let's see. Most of them are the same except for Saboady/Amazon, TB and Impel Down/Marineford. In Enies lobby he had black jeans, which were cool, but I really liked his TB outfit, that one was one of my favorites. However the Strong World outfit he wore when he raided Shiki's hideout (when he had the overcoat) was simply badass, but he took it off after about 30 seconds so it didn't really captivate me that much so his Thriller Bark outfit is my favorite.
Zoro- That Arabasta coat with the black and white stripes was pretty cool. It would've been even better if he fought in it. 2nd place would be his Saboady outfit.
Nami- Her Movie 7 outfit was good, even though it was from the Davy Back fight, the movie just added some very appealing features to it 
However, the outfit I actually liked the most would be her Saboady outfit, the movie 7 outfit comes in 2nd….....
Usopp- His skypiea outfit was cool, with the short sleeves, but the favorite outfit award for Usopp is a tie between two outfits: His exorcist outfit from the TB arc (was really funny) and SOGEKING!
Sanji- His water 7 arc suit with the orange shirt and black vest was cool, I hope he'll wear that again. The rest of his outfits were all suits with different colored shirts besides Skypiea, which was kinda cool but I prefer his Water 7 arc shirt.
Chopper- His enies lobby jacket was cool, I liked it a lot. Besides that he doesn't really wear anything at all. I also liked his post enies lobby arc outfit.
Robin- They're all sexy (I'm sorry but I can't judge them any other way she's dressed like a stripper in every single arc)
Franky- His Thriller Bark outfit was cool, with the yellow jacket and the horror island in the background (this was also why i chose luffy's orange outfit from TB), but I really liked his movie 9 outfit. Both are equally cool.
Brook- Well, he hasn't been around long so all what we've seen was his original outfit and the filler and movie outfits. I really liked his spa island arc outfit, but it ties with his strong world outfits. His original is nice but I can't rate it because it u know it's the original outfit. But I like it. Anyway his strong world outfits were nice because the orange shcemes matched with shiki's hideout and the bar and everywhere he went. If anything one of my favorite scenes in that movie was when he used yahazu giri on the guntai aris. His outfit from the flashback in the movie was funny, when he was dressed as a hippie. So I can't really make a decision, all of his outfits were good.
