There are many reputable makes of HDDs and many good sources. Even the unbranded are often perfectly good and made by well known names.
If you are happy with your existing HDD why note identify the manufacturer (Device Manager or Everest Home or similar) and Google for a 500GB version of that? You should get plenty of hits from names you know from this site, adverts, etc.
What one person thinks is a good manufacturer and source may be a nightmare for another.