What device and what kind of TV? If it's a 4k capable device connected to a 4k TV then you'll need a high speed cable. If either of those isn't true, then pretty much any cable will work. For what it's worth, I get my cables at the dollar store and I've never had a problem, but I don't need 4k. You will have fewer problems if you use the shortest cable that you can.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.