Clementine Lunar Image Browser 1.5
Interactive picture, based upon data from a spacecraft, that allow to settle the point of view.
http://www.nrl.navy.mil/clementine/clib/

Digital Lunar Orbiter Photographic Atlas of the Moon
Digital edition, with all 675 plates. Search by latitude/longitude, by name or by photo number.
http://www.lpi.usra.edu/research/lunar_orbiter/

Lunar Nearside Directory
Surface photographs from the Lunar Orbiter database and amateur astronemers, cross-referenced to Rukl's Atlas.
http://www.astrosurf.com/lunascan/sections.htm

Moon Panoramas
Compilation by Mike Constantine of high-resolution Apollo panoramas.
http://moonpans.com