I like both of them immensely. However I do have to say I like the original the best. Most of this comes from the drama involved I think. I mean you get to watch Hikaru mature from a guy who joined the military to impress a girl, into a serious adult, Also there is the ill fated love affair between Roy and Claudia. The scene where he dies in her quarters wanting to see her one last time before he dies always brings a tear to my eye.
However I love Mac 7 as well. When Basara sings Try Again in the final episode it gives me goosebumps. The first time I saw that I had the volume on the TV cranked up all the way, and I was almost cheering I thought it was so good.
That is the reason I love both of them though, The melodrama and the way Music helps to end the war in both series...it's just beutiful.