I've said it before, but I really like the Sampletekk pianos. Here is a list of piano libraries I've had experience with - in order of my personal preference: (I own the starred choices and have spent a bit of time with the others)Appreciate the replies with alternatives for Acoustic Piano.
1) real recording of an actual acoustic piano (not technically a library I know, but still my first choice)
2) Sampletekk White Grand*
3) Sampletekk Vertikal Jazz*
4) Garritan Steinway*
5) Pianoteq
6) EXS Various Pianos*
7) Ivory ( I have never been a big fan of this plugin - I know a lot of people really like it, but it never did that much for me)
8) Akoustik Grand* (Native Instruments, no longer offered)
I should also say that it all depends entirely on what kind of music you are recording. One instrument doesn't work for every situation.
(Sorry, I didn't mean to hijack the thread.)
kc