We went to WDW last year and (having seen pics of them previously) earmarked a couple of dollars for a few, not quite understanding what they were all about (the random element, trading, etc.). My DGF (sunset_princess) is an ex-cast member so had loads of experience with pins but these were something new.
We bought our first one on one of our first days there and got this little green lizard guy. We liked him so much we bought another... and another... and another! We have 10 now and have put aside another $100 for 10 more, we love them so much!
I think that the best thing about them is the fact that if you get a duplicate you can swap it in-store for something from the 'Mystery Box'; just ask the clerk! (If you get a really nice guy they may even give you a few hints as to where the really cool ones are hiding!)
It's all up to you if you get them, but they're so unique amongst collector items (Mickey-shaped, durable plastic painted or decorated in an astonishing array of designs, some by really fantastic artists, some of your favorite characters from all the years of Disney (and others)) that they'll really stand out from anything else you like to collect.
As for picking and choosing which ones you go for, we went for a variety - there's not much fun in picking from the same set over and over and over so we didn't! - and got a cool set of everything from arty to steampunk to vintage to the baby thing from TS3 (our least favourite one

) and a long-necked vulture!
If you're wanting to show off what you've got though, there's still no substitute to pins! I just really don't fancy myself strolling around with a couple of kilos of metal swinging around my neck!
Choice is yours but I (and the GF) think they're ace! Happy hunting!
