WD Black and Seagate are the best out of those drives you listed. Get WD Black if you are going to use it for more than 3 years, otherwise get the one that has cheaper price per capacity out of the two brands mentioned by me.
You can't compare it with ten-year old IDE HDD. It's not a fair comparison. I have no idea abou the Black 640GB which is stated to be quiet by many peoples, but the WD Black 1TB is surely much noisier than its previous gen, the Cavier SE which is noisier than the current seagate 12. In addition, the power consumption of the Black is more than twice as the Green drive which is very close to that of the seagate power consumption. 3 or 4W more can make the HDD much hotter. BTW, Samsung is .... very interesting.
Don't be a fan boy of sth you bought already. Others might also be looking at the post to make their final decision. If I were them, I would expect you to tell me the performance comparison instead of just saying "It's good and get it!" to me.
Try to get a Seagate or Cavier SE installed and you will know what I mean "noisiest ever". Although it is fast, it is just about as fast as seagate.
Besides, it consumes much more power than seagate. Hence, I would definitely get seagate if the warranty period were the same.
Any opinions on that External, speed and reliability wise? It's cheap and it'd be nice to be able to tote all my media around.
Don't consider the Black for external drive which is bounded in a little box without any air flow. The Green and seagate is the best choice for external
drives as their power consumption and temp are much lower than any other drives on the market, except for the extremely expensive SSD. For speed
and reliability wise external HDD without considering the price, the seagate will be the only choice for you then.