Within the Galaxy - Nebula
There are many different types of nebula: emsiion, reflection, dark, or any combination of those!
M42 - The Orion Nebula
NGC 2264 - The Christmas Tree Nebula (HaLRGB)
NGC 6960 - The Veil Nebula
NGC 7380 - The Wizard Nebula (HSO - hubble palette)
Barnard 33 - The Horsehead Nebula

DWB 111 - The Propeller Nebula (HOO)

The Pacman Nebula (LRGB)
IC 5070 - The Pelican Nebula
M8 - The Lagoon Nebula

NGC 2359 - Thor's Helmet