I just wanted to say thanks for the various replies so far. I've already picked up some useful recommendations.
In response to Dave James, I would say I am pretty immersed in jazz already. I have 9000 or so CDs and LPs, the vast majority jazz. In terms of Blue Note I have pretty much all of the 'usual suspects' and many more besides. However, there is only so much you can listen to ( let alone afford ) and I'm conscious that I'm probably missing out on some of the less well known titles. For example, Dexter Gordon's 'Doin' Alright' is a firm favourite of mine, although 'Go' and 'Our Man In Paris' are usually the ones at the top of the list. And, as someone commented, there are other labels ( eg Riverside and Prestige ) with some great albums. However, Blue Note has always stood out for me, both in terms of sheer consistency and recording quality over a vast output.
As far as tastes are concerned, I'm not a big fan of free jazz in general, although the occasional artist/title can be rewarding. Other than that, I'm pretty open to anything back to including the first BN titles.