[AJames]

I observed have many of the northern objects objects from Devon in the UK during October 1996 and again in October 1997. I used the northern addendum in Hartung as a guide for look at northern objects, though this list is probably misses some of the better objects. Ie. For me the best objects in the northern skies above +60 degrees declination, classed by type, are;

Open Clusters

Probably the famous "Double Cluster in Perseus" (NGC 867 and NGC 884), which appear in Hartung's main pages, but was not visible to him in 1968 from his Victorian latitude. This ranks as one of the best sight even in the smallest of telescopes, though our grand southern open cluster NGC 3532 in Vela (The Football Cluster) has brightest star over a similar huge area.
Another open cluster I liked very much was the "Christmas Tree Cluster"; NGC 1502 in Camelopardalis. I also enjoyed M103 / NGC 663 in Cassiopeia with it many red-orange stars. Both these clusters are fairly unique and have no real equivalent southern cluster that are populated with such older and more colourful components. Those in the south that are, are actually much fainter and less interesting.

Galaxies

I would personally automatically reject the M31 / Andromeda Galaxy as it is easily visible in nearly all the populated centres in our southern latitudes, but would add probably M51, M81 and M82, and M101 instead. Most galaxies in the northern skies, anyway, are quite invisible to most observers due to the vast areas of urban areas having light pollution.

Globulars

Northern Observer standard answer; "What's a globular?"

Double Stars

Among the many doubles, probably the best, all with wonderful colour contrast, as;
Epsilon Draconis
Eta Cas.
STF 3001 / Omicron Cep
Gamma Andromedae.

Others with an honourable mention would be;
STF 1694 32 Cam
Mizar / Zeta UMa
STF 2078 17 Dra
STF 2118 / Mu Dra / 20 Dra
STF 2863 / Xi Cep

Nothing in the northern skies compare to Alpha Centauri and Alpha Crucis. Only perhaps Polaris (which didn't impress me at the time) would be rated as an OK double.

Best Asterism : The Cepheus Triangle

The best asterism in the northern skies is the so-called Cepheus Triangle which is mentioned in Richard Allen’s “Star Names: Their Lore and Meaning” (1899). This small area surrounding the star Zeta Cephei (22h 10.9m +58d 12') has a nice little stretched out isosceles triangular asterism, being 1.3 degrees at its base and 2.3 degrees for the other two sides. This celestial triangle points towards the ENE (PA 70 deg), and is supposed to represent his head of Cepheus, and is likely one of the only recognisable feature of this entire region that is quite devoid of bright stars. Cepheus is represented in Greek mythology as an ancient Ethiopian King in which he shares with his wife Cassiopeia and his daughter Andromeda in the sky. This is shared with the yellowish 4.2 magnitude Epsilon Cep / 23 Cep / STG 10 (22h 17.0m +57d 03') and the white or yellowish 4.0v magnitude δ Cep / 27 Cep / STF 58 (22h 29.2+58d 25') - the classic namesake variable of the group of stars known as Cepheid variables. Both these stars are wide pairs but the former, epsilon Cep, is likely even unfamiliar to most northern observers because of it enormous width. I did observed both of these in 7x50 binoculars while in England during October 1997.

Northern Planetary Nebula

Favourite planetaries would include;

NGC 7076 Cepheus
NGC 7139 Cepheus
NGC 7354 Cepheus
NGC 40 Cepheus
IC 1454 Cepheus
NGC 1501 Camelopardalis
NGC 3587 / M97 / The Owl Nebula UMa
IC 3568 Camelopardalis

Perhaps the best of these is probably NGC 6543 and the Owl Nebula - but I'd select NGC 6543 in Draco as the "Top Dog".

For me, Cepheus is probably the best constellation in the farr northern regions of the sky. It is contains some twenty known planetary, three being NGC and three others being Abell. The brightest in the constellation is NGC 40, followed by the more difficult and larger NGC 7354 (22h 40.3m +61d 17') then NGC 7139 (21h 46.1m +63d 48'). These latter planetaries will probable require at least 20cm and 25cm, to see, which are likely improved in 15cm to 20cm using an O-III filter.

Of the lesser known ones, perhaps IC 1454 (22h 42.4m +80d 27') is next in line, but this is probably challenged by three other; namely Minkowski planetaries M1-80 (22h 56.3m +57d 09'), M2-51 (22h 16.1m +57d 29') and M2-52 (22h 20.5m +57d 36') followed by Abell 77 (21h 32.2m +55d 53'). All of these latter planetaries require at least 25cm to 30cm with an to see [O-III] filter - though preferably with a much larger Dobsonian.
A final planetary is NGC 7076, which is also known as Abell 75. However, this might be a bit too difficult for even the biggest apertures.

Passing Shot - ... and Wait for the Ricochet !

However, other than these, the best hemisphere to be in is the one we are already in. Sorry, though I loved observing the northern sky - except for one or two objects - you are quite welcome to have it...