I found SStiff and TSPP highly overrated....and although I don't have WWind or JD anymore - I miss them but was simply looking for a change....
I've found JY (and JD) underrated - if you approach JY for what it is not (deep like TSPP, nor a ton of toys like TZ) - its great fun and approachable by everyone...
MM is always mentioned in a thread like this - my thoughts are is that it is overall best pin I've played (I've never owned one and not burning to have one) but folks who don't have one - claim it's not that great, those that do feel it is the greatest and pinheads that I call hipinheads (hipster pinheads) dismiss it for abstract reasons - but if you just approach a pin without a lot of preconcieved notions - hard to argue that MM is probably the one that got a hell of a lot right!