"OldSkoolVerb is a freeware algorithmic reverberation AU and VST plugin for professional music production applications.  This plugin implements a kind of “classic” stereo reverb algorithm which is technically simple yet optimal.  It also produces a very clear spatial image that blends well with the mix.

OldSkoolVerb offers you a comprehensive set of parameters permitting you to achieve various reverbs ranging from plate reverb to room reverb to hall reverb sound.  OldSkoolVerb is best suited for non-percussive and soft-attack sounds like vocals, piano and pad sounds."