personally, still haven't managed to get hulu working - please feel
free to recommend a proxy/other method. reckon i'd use it a lot though.
Joost lost my interest (and IMHO damaged their brand) with poor
content and standalone player - haven't bothered with the in-browser
version yet.
ITV made a strange choice in using Silverlight - works OK on my PC but
still crashes my Mac browsers. They just don't have the content though.
iPlayer is great on the Wii if you use WiiPlayer to sort out the
interface, fantastic through a browser, kind of pointless on an iPhone
without access over 3G (though the recently-discovered TV-out
framework could make for a useful native application). It'd be nice to
access it through an Xbox 360 (a la netflix). DRM and Kontiki prevent
me using DL content (ditto 4OD - i'd rather use, gasp, bittorrent).
My PS3 toting-friend is overjoyed with iPlayer on his telly, whilst
another with Virgin Media never uses it.
Hulu notwithstanding, I think iPlayer's easily the best experience for
professionally-produced content, and the ease and speed of use makes
me choose it over the illegal method mentioned above every time.