I have been using PlayOn to stream Hulu to the tv for about a year now (first through Popcorn Hour A-110 and now through the PS3). Although, it can be a little buggy (have to restart every once in while), with the PS3, it seems to work pretty well and seems to be getting better. It was buggier with the Popcorn Hour. It is annoying that it only runs on Windows since this means I also have to run it on my partner's laptop (which he doesn't keep running all the time). The good thing is that you can try it out for free for 14 days.
I'll have to look into Plex.