My first few hours were spent clicking around trying to find something to watch at any given moment, before I realized I was at work and not sitting on my couch, and needed to consider how much this was pissing off anyone sitting near me. I've now mostly settled on watching music videos or the news, as both are relatively easy to tune out.
Having said that, it's only a matter of time until I start watching my favorite movies and shows (and bringing popcorn to the office, of course), and I personally don't think they should be allowed to reprimand me for it, since they're the ones who put the TV on my desk!!
Will let you know how far that argument gets me.