For Orthodox Ashkenazim, the most prevalent custom is to wear a tallis gadol with black stripes. In my area, I've noticed that the vast majority (of non-Chabadniks) wear tallesim with five thick black stripes of even width (on each side), while a smaller number wear tallesim with three black stripes, with the middle stripe somewhat thicker than the other two. (In both cases, this doesn't count the stripe nearest to the edge, which is usually made up of a number of very small stripes). What is the significance of the number of stripes on a tallis? Is five stripes simply the customary number of stripes for Tashbetz tallesim?
Tashbetz is a very specific model. It's Mishkan Hatchelet's most slip-resistant design.
More broadly, the vast majority of traditional black-striped talleisim (Prima A.A., Chatanim, Hamefoar) do indeed have five stripes. Usually the three-striped variety is simply because it's a smaller size in the width, i.e. across the shoulders, from one fringed side to the other fringed size.
For example the Kalil lightweight tallt is narrower and the smaller sizes (50, 55, 60) don't have enough room for five stripes. But I heard they actually went back to five stripes, at least on the size 60, so you may start to see that less.