Youtube now refuses to buffer videos unless I'm actively watching them. This is contrary to my normal procedure.
Herk. I hope that doesn't last long. It doesn't matter on dorm internet, but when I'm back home I plain can't stream videos in HD. Hell, the ultra-low-quality anime fansubs need to be buffered for a while before I watch them.
I never watch stuff in HD. Hell, I'm barely buffering faster than I can watch as it is.
We have decent Internet service at home, and we've got a good wireless router. It just happens to be on the opposite side of the house through several walls.
See, I had that problem, so I got a drill, bought a 100ft ethernet cable, and went under the floor. 
There is no "under the floor" here. House is built on a concrete slab 
And huh. Stuff now appears to be buffering while paused, if a little more slowly than normal. Perhaps it was just the one channel (for some reason).
On the plus side, you aren't going to go crawling around in a basement crawlspace full of mud, spiders, and 100+ year old whiskey bottles left behind by the original construction crew. Let's say that there were a great number of reasons explaining why we were able to move out of our tiny apartment into a house; it's been a ~15 year DIY repair/remodeling job. :|
But yes, I've noticed that as well, that sometimes it's dependent on the individual video for whatever reason.
Trust me, I know all about the underside of houses. One of the easiest ways to run cable line was to go through the crawlspace/basement when possible, and thus I did it a lot. Dead animals, broken glass, ventilation tubes with barely a foot of clearance under (or over) them, mud from recent rainstorms...you name it, I've seen it (and likely crawled through it when unavoidable).