I've debated this subject at length in my own mind, and was even thinking about it again this week (due to my new rifle in .260 Rem necessitating the purchase of new dies). Anyway, I've been using Lee dies on my .308 Win for years, and I ended up picking up another set of Lee dies for the new rifle (with both a neck sizer and a full-length sizer).
I can't sit here and tell you that Lee dies are better than other dies. But, similarly, I can't sit here and tell you that any other dies are better than Lee dies, though I will admit that some certainly seem more refined (and expensive). I guess I got a bit hung up looking at all of the fancy Redding bushing dies, seaters, and other such high-end dies. I figure I'll need to have a good motivation to spend a couple hundred dollars on a set of dies like those, and I just haven't yet found the need to do so.
In short, Lee dies may or may not be the best (and I doubt they're better than a $200 die set), but so far they've proven to be good enough for me... though I'm still thinking of getting a top-end Redding set at some point.