TheSw1tcher is about the only more traditional LP channel I still occasionally watch, mainly because seeing them suffer through dredge like Omikron has a great 'train wreck in slow motion' quality to it.
Heeeeey. I love The Sw1tcher/Super Best Friends. Their sense of humour matches up with mine so perfectly, and seeing them slowly driven mad by the absolutely godawful Omikron has been hilarious.
I don't watch LPs so much as just have them running in the background as white noise and something to flick my eyes over to every now and then when I hear something interesting. It's a great way of seeing games that I have some interest in, but not enough to actually play for myself, whether it's because they're in a genre I don't get along with or, in the case of Omikron, they seem utterly atrocious. I've always been interested in Silent Hill, for example, but I'm too much of a wuss to play scary games for myself so it's been nice seeing the Best Friends play them (constant jokes about fart gas might spoil the mood for some, but not this guy ). I'm hoping they're going to do Resident Evil 7 next year.
Otherwise, I like ChipCheezum a lot. He puts an insane amount of work into his stuff, making sure to show every little bit of the game and doing multiple takes to get his gameplay looking as interesting as possible. His Wonderful 101 LP taught me so many things I'd completely missed when I played that game. Supergreatfriend is another great one. He picks really interesting games to LP, and he's got a great voice.
Occasionally I'll watch a bit of Seraphim17 casually waltzing through every game on the hardest difficulty when I really want to feel bad about myself.