Visual observing is a fascinating activity, with a great emotional value that photos can't beat.
Sadly, light pollution in the cities prevents the observation of deep sky (galaxies, nebulae, clusters of stars), giving chances only to the Moon and Planets
My great passion is the observing of deep-sky: from a site with a very dark sky a medium sized telescope can reach hundreds of objects, and many more with the biggest ones.
When observing many objects it helps a lot to write down the observations, because the memory doesn't go too much far and beyond you can lose the count!
At the present time, I've got in my bag 1102 deep-sky objects, as well as 34 comets. This number grows slowly by some dozen per year, depending on number of clear nights.
Most of the observed objects are galaxies (699), followed by the open clusters and then by globular clusters, planetary nebulae and diffuse nebulae.
My observing sites are divided in two groups: country sites near small villages and mountain sites; from my home in Mortegliano, I ceased to observe deep-sky because of the light from street lamps.
Country sites (Osservatorio di Talmassons, countryside near Torsa) have a average limiting magnitude of 5.5, with peaks of 6.0 during winter; it is possible to see well clusters and the brightest nebulae, but they are limited for observing galaxies and the faintest nebulae..
Mountain sites (Matajur ~1250m, Zoncolan ~1850), even if they suffer from weather instability, are worth because give to the instruments the best performance. The contrast of the faint objects is superior, and the brightest ones become spectacular.
Furthermore with the biggest telescopes come within reach objects very difficult or "impossibles", like the famous nebula Horsehead in Orion, the dwarf galaxy Leo I, or the Pillars of creation in the nebula M16.
Here are two sketchs of the Moon made with the 200mm Newton, a day with average seeing in Mortegliano; the naked eye visual magnitude was fourth, but that didn't have negative effects on the Moon.
The beauty of the Moon at high powers comes from the tridimensional aspect of the details near the terminator, and also from their fast change, with variations in tens of minutes.
On the contrary, to observe the deep-sky, having the darkest sky is a fundamental need. Most of the deep-sky objects from the city lose their beauty, so it's necessary moving to mountains to observe them properly.
For observing nebulae, the use of a UHC or O-III filter makes a big difference in constrast and visibility, especially on planetary nebulae.