GVerb is the most complained about effect in Audacity. 

Main issues:

- has to be mixed with a duplicate to sound decent
- no presets {meaningfully named presets are very important to users)
- mono
- limited features
- inaccessible below the divider - built-in reverb preferred
- no Audacity reverb is shipped for Linux

GVerb is probably never going to be a good reverb (http://wiki.audacityteam.org/index.php?title=GVerb#Criticisms).

Freeverb3 seems a strong candidate (http://freeverb3.sourceforge.net/downloads.shtml). As far as I can tell the LADSPA-CMT-Freeverb3 at http://www.ladspa.org/cmt/plugins.html is less full featured, and undeveloped for 5 years. Steve said "it's likely to take a fair bit of work to get it working properly (it works reasonably in Audacity, but without presets and
with a dodgy "Freeze mode" button."

Freeverb3 VST works well on Windows, but there's six different builds, each containing eight different plug-ins. Steve says "the convolution reverb sounds terrific and they have some nice IRs available".

If we shipped a VST of Freeverb3 for Windows/Mac and a LADSPA port for Linux then the LADSPA version would apparently not permit presets - to achieve that, we might have to support DSSI GUI for LADPSA (http://en.wikipedia.org/wiki/DSSI).