I think I made it to season 3, and have not watched any more (of Brotherhood). I really should finish what is up on Netflix... (started watching Wolverine and the X-men :3)
I started watching the original series as it was coming out in English, and eventually got my brother and sister-in-law hooked on it as well. Once they caught up to current on it, they couldn't stand waiting any longer, so we snuck into the university's school of business and used their (much better than ours) internet connection to download all of the Japanese episodes we hadn't seen yet, and stayed up till ~6am watching them all. Good times.
I haven't watched all of Brotherhood in English, but the subtitled version was just as awesome as the first series.
Because I had to go to work the next day, so I had to stop watching. Then I forgot to watch more... Not even sure how much is actually on Netflix, I'm sure to finish it when I have free time for TV stuffz.
For the uninitiated, the difference between the first series and Brotherhood is that in the first series, the full manga hadn't been written yet, so past a certain point in the anime they made up a new story for the ending (which is still good).
In Brotherhood, they Anime-ized the manga's story, but the early episodes basically assume you've seen the original series, and speed through plot points until the stories begin to diverge.
The only thing I've noticed that they blasted over were the events in that town whose gold mine has kinda dried up, with the State guy who has the cheesy mustaches.