What are the most popular galaxies for which we have images?
Any such list is going to be terribly subjective. Since I'm an astronomer who studies galaxies, I'll go ahead and throw out a subjective list of the more famous, photogenic, and/or scientifically well-studied galaxies. The first six are in the Local Group (LMC and SMC are satellites of the Milky Way, M32 is a satellite of Andromeda).


Milky Way
Andromeda (M31)
Large Magellanic Cloud
Small Magellanic Cloud
Triangulum (M33)
M32
Sombrero (M104)
Pinwheel (M101)
Whirlpool (M51a)
M64 (Black Eye)
M74 (NGC 628)
M81
M82 (Cigar)
M87
M100
NGC 891
NGC 1068 (M77)
NGC 1300
NGC 1365
Centaurus A
Cygnus A