Hey there, Felix.
I'm a bit confused by the title, where it says that you need a 1TB drive and in the post you say 500GB. But that doesn't matter that much. I assume that you're looking for a portable external drive (2.5") and not a desktop one (3.5" which uses external power source)? If this is the case, you could take a look at the WD Elements Portable HDD. It's a simple and reliable USB 3.0 external drive, which has models with capacity range of 500GB-2TB (so you can get either a 500GB or 1TB one as well). It comes with a limited warranty of:
Americas -1 year
EMEA (Europe, the Middle East and Africa) - 2 years
APAC/Japan - 3 years
You can take a closer look at it and its features here:
WD Elements Portable
Hope that helps.
Boogieman_WD