I really think this depends upon the club, setting, course style, and region. It seems more appropriate for a striped pole and number flags on some traditional golden age designs while a wooden Cheesebrough pin may be more appropriate for a rural woodland course. I would say the best are those that respond to the character of the course and its community, however broad that may be.
Personally, I prefer the thin pole, if for no other reason than that it makes me feel stronger (think Seinfeld's hotel soap observation). I like the black and white striping, especially when horizon greens are present. Flags are usually best when one color and numbered, but once again it is all about the local flavor. Originality is also applauded, such as Crystal Downs's half stripes, Merion's Baskets, Belvedere's four square, or any unusual shape or pattern or anything that adds a genuine character to a place.
John K,
Crystal Downs uses Red, Yellow, and Blue positional flags. That's a highly rated course. See Brian's photo of #9.
Jim K,
I played a course that had American flags for the Fourth weekend, and they had little stands at the sides of each green, "so that our NATION'S flag need not touch the ground. A really cool gesture, though there were a lot of hole locations really tight to the edge of the green that day for some reason