I am a big fan of tights.
I wear cotton tights in the winter. They keep my legs infinitely warmer when I'm in skirts (which is most of the time!). In the fall I wear lighter tights. When I wear light-coloured skirts, I wear sheer, skin-coloured nylons.
I have not tried a garter belt, but one thing I could tell you is that I'd be constantly worried about the clips breaking and the nylons falling down! I am worried enough about holes when I wear tights. I'd be downright paranoid in a garter belt.
I've been very interested in trying out "thigh-highs" - just because tights can sometimes be annoying if the top is too tight around the middle (silly control-tops...).
Though I can tell you, I will definitely wear a garter belt on my wedding night........................