I mostly watch youtube from my laptop, but every once in a while I'll airplay my screen to the appleTV in my room. I really am not a fan of watching videos on my phone.
I love the TPR channel for the crazy out of the way parks and coasters featured. I'll also admit I rarely do the playlist/suggested videos thing. If it's not something I'm subscribed to, I probably won't see it (unless I'm forwarded from another site which embedded it). But hey, I've subbed the TPR videos for a while now.
*Edit: I also wish there was an option for reading comments. I love to read hilarious responses, but don't comment much (thanks to Google+ being shoved down my throat)