One of the most common complaints I hear directed towards Brotherhood is that it lacks the pathos that the first series had. While this neglects the obvious fact that said pathos was all filler that wasn't present in the manga, this complaint has made me realize that BONES didn't put anywhere near the effort into the 2nd series as they put into the 1st series.

In what order should I watch the episodes from FMA and Brotherhood in order to form a cohesive plot with the angsty pathos of the first series and the compelling plot of the 2nd?

Hi Zenoseiya, you might find the discussion on this thread interesting:
Suggested "Converged" Viewing Scheme for FMA-1 and FMA:Brotherhood anime.

Check it out, and please let us know what you think.