id go with the seagate, i have 2 of the 7200.10 (250gb) and cant fault them. will be getting 2 of the .11's (500gb) when i get the money.
i have had WD in the past, very good HDDs, Samsung i hate with a passion, had a 120 and lost everything on it, it was noisy and just a poor performer IMHO, this was a few years back, dont know what they are like now