I am on a big turquoise and tangerine kick lately; that's what's currently up on my design wall and those are the 2 accent colors I picked for my (mostly white) sewing room.
Blue & brown is a more classic combo that's another favorite of mine.
I recently did a quilt for a little girl in pink and spring green that turned out very cute.
Grey & yellow seems to be a popular combination, maybe starting to fall out of fashion a bit now but I like it and have fabrics stashed to make a gray & yellow quilt.
Denim blue and worn red, for that "Americana" look...