I know I am in the minority, but I prefer the regular FMA. I think brotherhood lacks the emotion and pacing of the regular series (at least the first 10 or so episodes). I would watch the regular series before you watch brotherhood. It is by far one of my favorite series of all time.
Definitely the minority, but I think I know why. Have you finished it? I agree that the original series does a better job of setting up the foundation, but as soon as it starts diverging and going off the manga's path it becomes so ridiculously inferior. If you have only watched a bit of it, then you're missing out on the full experience.