AT A RECENT COUNT THE MILKY WAY CONTAINED:
1,776 Star Clusters
Optically visible open clusters and Candidates (Dias+ 2002-2007)
http://webviz.u-strasbg.fr/viz-bin/V...source=VII/229
150 Star Balls
Catalog Of Parameters For Milky Way Globular Clusters (Harris, 2003)
http://physwww.physics.mcmaster.ca/~harris/mwgc.dat
http://cdsarc.u-strasbg.fr/viz-bin/V...source=VII/202
66,887 Gas Clouds (including 2,177 optical sources)
Catalog of Star-Forming Regions in the Galaxy (Avedisova, 2002)
http://webviz.u-strasbg.fr/viz-bin/V...-source=V/112A
5,046 Dark Clouds
Atlas and Catalog of Dark Clouds (Dobashi+, 2005)
http://cdsarc.u-strasbg.fr/viz-bin/V...ource=VII/244A
1,143 + 903 = 2,046 Gas Balls
Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker+, 1992)
http://webviz.u-strasbg.fr/viz-bin/VizieR?-source=V/84
MASH Catalogues of Planetary Nebulae (Parker+ 2006-2008)
http://webviz.u-strasbg.fr/viz-bin/V...e%3DMASH/mash1
ALSO OUTSIDE THE MILKY WAY THERE ARE:
983,261 Milky Ways (to B magnitude 18)
HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
http://cdsarc.u-strasbg.fr/viz-bin/V...source=VII/237
That should keep the DSO observers busy for a few nights!
Objects in the LMC and SMC are not included in the lists above.