Gonna leap into the fray and offer some back-up tohere. It's no secret to anyone that's read my OTAKU COMING HOME features that I love FMA in all its incarnations (manga, original series, and BROTHERHOOD).
While I disagree with his critique of BROTHERHOOD and the original manga,is right that the original FMA has the simple benefit of offering a different take on the story. Do I like it better than BROTHERHOOD? Nah, but I enjoyed it immensely and respect Studio BONES for the work they did, ending included.
And speaking of that work, I see a lot of people who prefer BROTHERHOOD solely because it's "true to the manga," but do keep in mind that Arakawa specifically wanted the first series to deviate from her work (which was also still in-progress at the time). I don't think it's fair to fault the original series for its differences when the mangaka neither had the material to provide BONES, nor the inclination to have the series follow her work.
For, my advice would be to seek out the subs - I wasn't a huge fan of the dub in either series, but the original was pretty much the pits. Watch it all the way through or pick up where the biggest deviations occur, it's your call, but if you like the franchise it's probably not something to be written off.