They're not as popular as the series mainstays, and they don't have the advantage of being "ZOMGBISHICLEAN" like Edward or Roy, but in the short time that we knew them, they really spoke to me. They can be called a lot of things, like "Ed and Al meet the dark side." But I saw something more profound and interesting in them. I know not as much of a deal was made in tha manga, but I love characters that give us a look at good and evil. It's no question that the 48's were evil people, but... as Ed said, they were also human beings. And unlike someone like Barry, they recognize their misdeeds, while at the same time not saying cliche things like "I'm sorry", and "Wow, we're all going to be great and happy from now on." There was a shade of grey and tragedy painted over these two, and when the younger 48 sacrificed himself, I was in tears. I was forced to see it all over again, when Lust murdered older 48.
That's why I really love these two as characters. There's more to great writing and a great series than how they write the main characters, after all. In the 48's, you see stuff about good and evil, shades of grey, hopelessness, and tragedy, all wrapped up in a large rusty suit of armor...
I AM NOT OVERANALYZING THINGS! YAAAAR!
*ahem* ... anyone else out there got something to say...?