I want to make a video for my friends and i can't decide whether to play lead or rhythm?
Which part are you best at playing?
Lead is usually more entertaining and I would normally aim to play it but if you're playing something like Bleed by Meshuggah though I would say Rhythm aha.
I like to mix the two, try and incorporate some of the lead into your rhythm playing. It's probably more difficult that way but in my opinion it sounds a lot better and catches more of the detail in the song. Sometimes lead parts are "big" enough to take up a lot of space though so it really depends on if your song has lead sections like that.
If I'm playing a song solo just to show it to someone, I tend to do both. I just play whichever guitar has the cool parts going on, as long as it doesn't interrupt the flow