Depends on the team I am playing so I match colors with all of them.
But my favorites would have to be the Bass one and the Original one. Recently started to like the Axl color too, but the Black one is the one I use the most.
I have no idea why capcom didn’t choose the regular Black Zero, which IMO is way better.
I like the black one because I love the Black/Yellow/White color combination on all characters. So sexy. I used to play Zero/Dante/Tron in those colors. I miss that team so much. ;_;
The Vile color is my favorite, followed closely by the Bass colored Zero (Which I just call black armor Zero because fuck it.)
Even though Zero was my childhood hero, I always thought Vile was cool as hell. Purple is also probably my favorite color, if I had to choose one.
Also! My MvC2 team dressed in all purple (Mags, Cable, Psylocke) so I felt like the addition of purple Zero color would be a great chance to remember that team.
I was hoping they would have put that in, i don’t know why they didn’t, is way better than the Bass color anyway.
I go with Megaman Zero, it’s what motivated me to play the character in the first place. If i had to pick a second it would be Vile color, that one is beast.