As much as they are all great sights to see, I had to choose 'Other Galaxy' as it is the only title that comes close to my favourite sight: Abell 539
I have never seen this object visually with an Eyepiece, but it looks great seeing it 'Live' with my Mallincam.
Abell 539 is a Galaxy Cluster in Orion containing 50 Galaxies all beyond Mag 14.
The part that takes my breath away is that it is like looking at the Ultra Deep Sky South image taken by Hubble and yet I can see it 'Live' on my Computer monitor!
I have shown this object 'live' on my broadcast a few times and the viewers all go 'wow, look at them all'
Here is an excellent photo of part of Abell 539 taken by Rolf Wahl Olsen, so you can see why I love this object (Galaxy cluster) so much: