i have been using HIT/TOS for a few years already. so far so good. they are cheaper than others and 7200rpm.
WD are also great, if you know the difference between their colours. many people choose WD hard drive model based on the "colour". i have heard someone say his gf like the colour green so he got the green model for her. later she complained about why her computer is so slow.
ps. green is best for external hard drive. it is 5400rpm so it uses less power, not as noisy and it is the cheapest within WD range.