After a hefty amount of troubleshooting (I fucking hate dealing with networks) I got my 360 to connect with my wireless router and through that, connect to my computer’s external hard drive through Windows Media Center.  The actual interface isn’t so great and I need to really reorganize how all my movies are currently set up, but once I found what I was looking for (I watched 50/50), I had no connection issues or buffering issues or anything like that at all.  Really the only limitation is my TV, which is an older rear-projection so the picture’s not the best.  Other than that, it went much better than I was expecting.