I've applied the firmware update to two of my three affected 500 GB drives, and had no problems. The third drive has been in 24x7 service for about a year and *crosses fingers* hasn't had a problem, but I should go ahead and put the new firmware on it soon...
Unfortunately, Seagate's support website is on the fritz right now... the pages with the firmware updates aren't coming up.
As for "what brand to get" - as far as I'm concerned, all hard drive makers suck. At work, I have a stack of dead WDs...
UPDATE: Seagate's support site is back in working order. Go
here to find firmware updates.