Larue Stealth has been the most consistently accurate for me. 1 in 8 twist. It's a nice profile that's pretty heavy but not ridiculous. Also chambered in 223 Wylde. Price is higher than it used to be, but isn't that true of everything these days. When they were $225, it was a no brainer.
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Larue Stealth
Lothar Walther (get the LW50 SS)
Something machined from a quality blank by somebody like White Oak
Ballistic advantage is kinda sucky in my experience. I have several of their barrels because they're cheap (like $60), but the accuracy has always been pretty mediocre at best.