i think it depends on the situation. purple looks pretty next to yellow and green. blue looks pretty next to yellow and orange. orange looks pretty with yellow, red, and blue. yellow looks best when accompanied by another color, while most of the rest look really nice standing alone. but overall i would have to say purple, for it fits in with most situations. but i mostly love purple when it is accompanied by green. maybe its because the majority of earth is covered in green plants, and thus purple looks nice while accompanied by these plants. also, the majority of non-green plants are purple plants (either that or red) and thus when i think of purple, i will commonly think of these plants, standing out among the rest of the forest. i also have a purple plum tree right outside my house, and its a really pretty tree, so thats probably another reason.
if not purple then blue, it does have an air of mystery around it. also, blue is the color that holds the most energy through its wavelength, and thus to me it is a symbol of strength. also, blue is one of those colors that looks best when alone, and thus i can think of blue as a pretty color by itself, rather than purple, in which i always think of purple and green.
if not purple or blue, then i might say green, but again, only because of purple.
and if none of those, then any of the rest. i have little feeling for the rest of the colors, and again, it all depends on the situation.
My favorite color is Teal~!~<3 Hmm..just is, don't really have a reason. *shurg* But I picked Green for the poll because mine wasn't up there and it's my bf's favorite color. Before Teal my favorite color was Blue but that was a long time ago. Haha.