Well, the only LPers I really watch right now are Supa, Jaco, Akane, a few Minecraft LPers, and Proton Jon, all of which barely never update. Even though I stopped watching him, I think I'll have to say Chuggaaconroy is my favorite. When I saw his Wind Waker LP, I was hooked. He not only inspired me to make my own LP, but without him, we wouldn't even be here right now. He introduced me to TheSpeedGamers, who inspired me to start SMB. I stopped watching him when he started his Okami LP though.. I don't know why, (and a lot of people are gonna hate me for this) but I just can't get into Okami. I acknowledge it's a good game, but I just couldn't play through it (or watch it) without getting bored. Alright I'm getting off topic here.
Wait.. Supa is the one who introduced me to Chuggaaconroy.. I guess that makes Supa responsible for my LPs AND SMB.. I change my answer, SupaKirbTV is my favorite LPer.