Western Digital always. I have Greens and Blacks and Raptors. If you are using as boot disk no one beats their speed and I/O. I have had 3 failed Samsungs, 2 Failed Seagates, and 1 failed Hitachi. So far 0 failed WD's. External or Internal. I also run 2x500GB FW800 Passports and 750GB MyBook eSATA/FW800 AND an ancient 320GB media monster thing with USB card reader. Anyway even with all my "luck" it is hard to say anyone else would have the same experience.
I would also agree with you. WD drives are very good. We use lots of them at work & they've withstood some very demanding, long computing sessions day after day.