Loaded question for sure. Most guys like what the have and recommend that as "the best"... I like (and run) the Supertrapp SuperMeg. Once you get over the look of no opening at the end of the pipe it's all good. Makes good power, improved my MPG when cruising, sound does not over power the radio or casue me to want ear plugs. I have run it with the open end cap, exhaust sound is loud in that configuration but works better with the closed end cap. The choice is yours but don't rule out the Supertrapp in your decision process. Ask a couple tuners what they think about the ST. The go with what you want & what your wallet will allow.
I had Bub7's on my Street Glide and will be installing them on my Roadie shortly. With the steped header pipes I had a slight gain in hp and torque after dyno. Nothing sounds better than Harley in stereo.
if you want to see and hear many types of exhausts, when it's warm again, go to a big harley dealership on saturday morning and you'll hear and see a lot of choices. by the way, winter still sucks.