As I understand, HDMI cables offer better sound and video connections than three-pronged RCA-style plugs and optical cables. They also carry video as well as video, so you need fewer cables. I have two HDMI cables connected from this TV to my cable box and Roku box, with the third HDMI output unused. I would have used it for my external speakers, but they have only optical inputs. As for brands, Best Buy's Insignia cables have worked fine.