What is a quality external 1TB drive that I can get for my iMac?

I purchased an iMac 2 years ago with a 500GB hard drive with the assumption that it would take me about 4 years to fill up. However, I am now starting down 64GB of space left on the drive.
I would like to find a good quality 1TB hard drive to use for back ups and such. I’m a high school student now, so I will most likely be taking this to college. As for price, something under $150 is great, but under $125 is preferable. I can use that money for gas.