Hiiii! I have been researching external hard drives for my PS4. Im a FO4 addict and it is taking up 90% of my space. What Do you use to expand memory/add space to be able to buy more games?

I'm torn between cheaper and more expensive options. Just because something is expensive doesn't make it good. And sometimes cheap can ruin everything. What do you use? What have you used and advise against? I want something I can plug in and just have it live with my PS4 with enough space on it to download whatever I want. Thank you :-D