Metoprolol, Atenolol, Propranolol, etc. are all beta-blockers and are all purported to do the same thing. I'm confused why there are so many and how do I know which one is better than the other?

When I was first diagnosed with HBP, my doctor, (not a cardiologist) prescribed Atenolol, which seemed to work. After visiting my current doctor, (a cardiologist) he took me off Atenolol and put me on Metoprolol which seems to be working okay also. But I think this drug is giving me some pretty awesome dreams! Some scary but mostly fantastical and outer worldly! Wow! I don't recall Atenolol giving me that experience...

Anyway, I digress. My point is my confusion with all these drugs that do the same thing. I mean, is one better than the other? Is there a way to find out? Maybe someone here can shed some light about this? Thank you!