Depends
entirely on what you're using it for..
I have the troy bar for basic upper body or endurance work.. its very lite, easiest to load up.. I use it for up to about 60#..
I also have a CAP 1" barbell.. weights 15# and is threaded. Pain in the ass--yes, but its good for loading up to the early hundreds and I use it heavy for deadlifts, benches and such as it's easier to wrap my hands around.
The olympic BB weighs 45# and is unbeatable for heavy leg lifts. You need a squat rack of course, but its great for squats.
Its best to use for heavy weight work where the BB is on your BACK.
I say this because the CAP threaded BB, im assuming because of its shorter length and (more so) cuz of its smaller diameter, feels a lot heavier on your back than the olympic, which balances heavier weights nicely.
So all three have their respective place, it just depends on what you'll be using the BB for