I have Sky HD and only subscribe to Sky Sports 1. So not even the full sports package and no movies at all (movies suck anyway, just repeats all the time) and i still think HD is worth it.
Its personal opinion to say the other HD channels Sky have are rubbish or pointless, i think they are pretty good most of the time. Nat Geo Wild, Discovery, C&I, History, Sky1 and live performances on Sky Arts 1+2 are all great. Plus the now non exclusive ones like FX and C4 are really good too.
Good amount of channels plus HD for £39 a month.