You will find many examples the work of Antonio, Fred, Richard, Morio, Thierry, Steve and Patrice in Inconstant Moon's nightly tours.
Jomo's Home Page presents the mondbilder (moon images) of Prof. Dr. Johannes M. Ohlert.
Bob O'Connell runs the ALPO Lunar Selected Area Monitoring Program, which contrasts the appearance many lunar features at different times of the month.
Pierre-Olivier Pujat et Jean-Philippe Cazard of the Toulouse-based Société d'Astronomie Populaire have to overcome a variety of several technical challenges as they create their images using a 100 year old 190mm (7.5") refractor.
Their fellow countryman Gérard Therin's Images à Haute Resolution - photographic and CCD high resolution images - reinforce the suggestion that lunar imaging is undergoing something of a French revolution!
If you feel inspired to create some images of your own you should take a look at Michael Oates' detailed introduction to Lunar Photography.
Amongst the professional organisations, one of the best sources of lunar images is the NASA Jet Propulsion Laboratory site, which includes a searchable catalog and an image tailoring system.
US Geological Survey maintains a nice library of processed Clementine Images,
whilst the Naval Research Laboratory provides a Clementine Lunar Image Browser which allows you to zoom in on a global composite image.