I have long been fascinated by the way sellers of Esterbrook pens include a nib - often, on the bay, including the number of the nib in the item title as if that is somehow inherent to the pen itself. Somewhere in my 40 years of collecting, I lost that association and always think of the pens, on the one hand, and of the nibs, on the other hand, but not really as essentially linked. If I am shopping for a pen, I want a particular pen and am not really concerned about the nib that comes with it; if I am shopping for a nib, I'll even weigh buying a pen I don't want if that's the only way I can get that nib.
I doubt I can ever do it, but one of my Estie fantasies is having a good (if not NIB) example of every Renew Point that Esterbrook ever made. As it is, I have about 45 individual nibs, but that includes a lot of duplicates (once you get obsessed with nibs generally, the next stage of the illness is becoming obsessed about individual examples of each nib; alas, "new in box" doesn't really mean anything except that there is a box; if you can't inspect the pen in person before purchasing, you may or may not be getting a "new" point); I seem to have about 16-20 different model examples (the exact quantity depends in part on whether I should count perfectly functional points that have some damage to the feed, and in part on how many I have tucked unthinkingly into a drawer and might find again some day when cleaning).
Despite -- or perhaps because of -- all that, I can't tell you my favorite. Because so many of those being sold have been heavily (and, I presume, lovingly) used, they are all different, and each also works slightly differently in different pens. I am almost amazed Esterbrook was able to sell them as they did - if I could go back in time, I'd want to grab 10 truly brand new nibs of any single number and a Dip-less pen and sit down to see how standard they were back when you had no doubt they were "NIB."
That said, I write small and therefore like the finer points much better, usually those in the 40s and 50s (e.g., 1421, 1550, 1551, 2048, 9051, etc.). Oddly (to me, anyway) I find I often like the 1000 or 2000 series better than the 9000s.
So, which do you have, and which are your favorites? How often do you interchange them?