In my earlier story on 3C 273, I promised to cover some other quasars that are within reach of urban astronomers. In fact, there are four quasars brighter than about magnitude 14. While this may sound pretty faint, because quasars are star-like, you can use high magnification to darken the background and get enough contrast to see them, even in washed-out skies. Under favorable conditions you should be able to see all four of them with a 10 inch (250mm) telescope from your front yard. (NASA artist's impression of a quasar.)
The brightest of the four at magnitude 12.8 is 3C 273. The next brightest is Mrk 421 in Ursa Major at magnitude 13.3. Both of these are within reach of a 6 inch (150mm) telescope, and easily visible with an 8 inch (200mm) telescope, even in urban skies. The other two are more challenging: Mrk 501 in Hercules at magnitude 13.9 and OJ 287 in Cancer at magnitude 14.2. Three of these, Mrk 421, Mrk 501, and OJ 287, are not only quasars, but blazars, which means they are highly variable in brightness over relatively short time periods. This is particularly true for Mrk 421 and OJ 287.
Quasars are cool objects in and of themselves. But there are other reasons that make these fascinating objects. One is the tremendous distances involved: 3C 273 is 2.5 billion light years away and OJ 287 is over 3.5 billion light years away. They are also powered by massive black holes: Mrk 421 has a black hole of about a billion solar masses; OJ 287 has a binary pair of black holes, the primary weighing in at 18 billion solar masses—the largest black hole known.
Now finding specific 13th and 14th magnitude "stars" can be a challenge, so if you are interested I have a full set of finder charts for all of these....
Orion is not only the best known winter constellation, but it is also a great urban constellation. Thanks to its distinctive arrangement of rather bright stars, Orion shines through in heavily washed-out skies, even when few other constellations can recognized. It is also the home of the Great Orion Nebula (M42) big, bright, and easily visible even in washed-out skies. However, M42 is only the most famous of many interesting astronomical objects in Orion. And best of all for urban astronomers, quite a few of Orion's objects—like the constellation itself—can be enjoyed in light-polluted skies. Here is a run down...
Amazing! Another supernova within reach of urban amateur astronomers has appeared in galaxy M101 in Ursa Major. Supernova SN 2011fe (also known by its preliminary name of PTF11kly) is already brighter than 
The Messier catalog lists some of the finest objects in the northern skies. Observing all of the Messier objects is one of the classic rites of passage for amateur astronomers. There are also a variety of challenges related to the Messier Catalog, the most famous of these being the Messier Marathon: a race to see all of the Messier objects in a single night. There are also binocular Messier challenges and photographic Messier challenges. My own addition to this is an Urban Messier Challenge: a list of Messier objects that are particularly challenging for urban and suburban observers dealing with skies washed-out by light pollution. In dark skies you can see all of the Messier objects with a 3 inch (75mm) aperture, but with heavily light-polluted skies you’ll have a hard time seeing the Messier objects on my urban challenge list even with significantly larger apertures. Here is the challenge list...
Jupiter offers great observing opportunities for urban astronomers. It is very bright, easy to find and shows interesting details even in small scopes. A view of Jupiter through a telescope will never fail to impress your family, friends, and neighbors. It’s relatively large size, cloud detail, and the ballet of its moons make Jupiter my favorite planet to observe. But after you’ve stared at Jupiter for the 20th time, then what? Well, here are few ideas of things to look for that should keep you busy for many nights to come...
For the second lesson in the 
Star-hopping is one of the most valuable skills in amateur astronomy. In the days before computerized mounts and GPS, star-hopping was the only way to find interesting objects. Thanks to the steady march of technology, not as many amateurs today are proficient star-hoppers. In fact, quite a few amateurs have never star-hopped. Still, for many of us without computerized mounts, star-hopping remains a critical skill. Washed-out skies in particular can really test your star-hopping skills: when only 3rd or 4th magnitude stars are visible, it can be a pretty long hop from the nearest visible star to your target. Even if you have a computerized mount, star-hopping can be useful in light-polluted skies: with many faint fuzzies at the ragged edge of visibility, star-hopping techniques can confirm that you are indeed looking in the right place.
In a 
For urban astronomers, galaxies are consistently disappointing. Galaxies that are stunning from a dark-site can be stubbornly invisible in even mildly washed-out skies. A very slight loss of contrast is enough to hide spiral arms, dark lanes and any other structural details. What makes galaxies even more frustrating is that none of the usual tricks for enhancing contrast work on them. Because they are extended objects with low surface brightness, increasing magnification just makes their already faint and diffuse light even more diffuse and fainter. Because galaxies radiate primarily stellar light, narrowband filters which can be very effective on emission and planetary nebulae don’t help at all with galaxies. So what’s an urban astronomer to do? Just give up on galaxies? Well, luckily there are a few galaxies that can be reliably seen under washed-out skies...