My first dies were a set from RCBS that I bought almost 20 years ago, and they still work fine. Since then, I've bought more RCBS dies than any other brand, and have been very satisfied. I have over a dozen full sets of RCBS dies plus various accessory dies (e.g., trim dies, added crimp dies, etc.).
I have a few sets of Lyman dies, and a few Lyman accessory dies, and as far as I can tell, they are every bit as good as RCBS.
I have one set of Hornady dies, and I like it. The sliding sleeve in the seating die (to align the bullet with the case mouth) is a nice feature.
I have a few complete Lee sets, and numerous single dies from Lee. They are not bad, but I generally prefer the others, all things considered. The Lee taper crimp dies that I added to several older sets (so I could seat and crimp in separate stations on a progressive loader) work great. I have a Lee "universal decapping" die that I use regularly and it works very well. I have had some problems with their "factory crimp" dies, though they serve a purpose.