In no particular order. Unless otherwise indicated, all these sites are in English.

Marco Guidi's planetary high resolution
Melis Cornelis-observatory by Corne Hoogendoorn
Excellent astrophotography gallery by Neo
I See Far Ivar Kooren
Views of the solar system by Damian Peach
La web de astrofotografía de Ramón Delgado (Spanish)
Ed TingTelescope Reviews
Astrophotography by Dennis Put
Marco Guidi's high resolution astroimages
Astrophotos by Jacob Bassøe
Notte stellata, blog by Davide Manca
JTW Astronomy astrophotography solutions
8" F/2.75 ASA Astrograph Gallery Albert van Duin
Marcel Ooms (Dutch)
Ronn Franken Stardust Observatory Stadskanaal (Dutch)