IMHO, brake fluid and properly bled brakes are more important than pads. I change my ATE DOT4 every year. Castrol DMA isn't bad either, and is easy to find in a pinch. Don't forget to bleed the slave cylinder...
EBC makes good pads with their Greenstuff, and you can't go wrong with OEM BMW. I've also used Akebono ceramics before on some FWD cars, I liked them. Hawk and Axxis make good stuff too, but I'm not sure who owns them anymore.
I'd avoid the Raybestos stuff and mostly anything else you can buy at auto parts stores. I haven't had a lot of luck with them, or their worthless "warranties."
Don't get drilled disks, they're a waste of money. Go for the ATE grooved ones, or Brembo stock.