a seriously good headset is the fsa orbit extreme. but i would go chris king. they really are that good. have a look about. can be found 2nd hand for 50. a blue one on stw if thats any good
I'd go for a Hope too. I've had 2 of 'em and they were both excellent. Funnily enough I serviced mine for the first time in 15 months tonight. The grease had discoloured slightly but all was fine.
The following link will give you a bit more insight into the construction and design:
http://www.hopetech.com/database/Headset_expl.gif
They come with a Hed Doctor which replaces the start fangled nut and are really, really well sealed.
Nah, I had one of their original ones (virtually the same design) on a bike about 5 years ago, which I then sold after nearly 3 years of use when I switched back from sussers to hardtail. Then when I bought my Cotic about 18 months ago I had one fitted as an option with the frame.
To be honest, having stripped and cleaned it earlier it still looked almost new inside - can't say fairer than that.
If you've got the money then go for a Chris King. They are by far the best headset out there and will outlast a good few bikes! They are definitely worth the extra outlay as they will probably save you money in the long term.
If your budget won't stretch that far, then, as a few people have said already, go for a Hope headset - They're excellent quality and very durable