IMO, don't buy Sky+ unless you really want to record off one Sky channel and watch a different one (that's what you'll pay the £10 a month for).
Instead, buy a personal video recorder (i.e. HD + DVD Recorder combo). We just bought the Pioneer 520HS for Crimbo and it's really great. £370 from Empire Direct.
Admitedly, that's about £170 more than the Sky+ box, but it has a 80gig HDD plus a DVD recorder built in, and no £10 a month subscription. That gives around 35hrs or good quality (SP) recording on the HDD.
It's one of those "I don't know how we managed before this" type of devices. Very much recommended.
I'm now capturing all those episodes of NYW in top quality (including the new series). Best of all, you can edit out the adverts very quickly (something which Sky+ doesn't allow you to do I believe).
Martin