The Swiss Confederation Cross flag looks great… It’s symmetrical in every way, horizontal, vertical, diagonal, point-symmetrical and rotation-symmetrical. Plus it is square and thus looks good in every “orientation” if there is such a thing with this design. Oh, and the colors don’t hurt your eyes, very important if you’re surrounded by them ;-)
The flags of the cantons are all squares too. The flag of Valais / Wallis is on the left half red, on the right half white, with tree columns of stars, two of four and one in the middle of five stars. The left column of stars is white, the right column is red and the stars in the middle are half red, half white. This most probably indicates the bilinguality of the canton, with four Francophone cities, four Deutschsprachige cities and five which are bilingual themselves.