Strings!

[eppertheleper]

i too will keep an eye on this - i am always dissapointed when i go near any electronic strings. i use reason for all this stuff but the strings imho are week (compared to real strings).

Horns are notoriously bad, too. If you've spent any time around the real thing, impostors are obvious. I just take my violin to the studio for string sounds, but not everybody has that option.

[rhythmtech]

for real strings - LA scoring strings library for kontakt (very expensive)
for old dusty strings - any of the many mellotron vst instruments.
for horns - vir2 horns library for kontakt.

as already stated horns are very hard to make sound real, vir2 library has expression included which goes a long way to help the realism. any other horns ive heard have been pretty fake sounding.