Autumn blaze maple, Acer fremanii. Sunburst honey locust, Gleditsia triacanthos var. inermis 'Suncole.' Seedless sweetgum, Liquidambar styraciflua. Redbud, Cercis canadensis.

Would go with a flowering tree on the smaller side, such as redbud, dogwood, tree lilac, burning bush or the like.

Just my .02. Nothing wrong with lilac but it does get a little boring the rest of the year, and a lot of the foliage on the lilac will be below the fence. There is a cool tree called "Chinese Lilac Tree" Syringa reticulata subsp. pekinensis (formerly known as Syringa pekinensis) which is a very popular small street tree around where I live. Here's a link to more information about it, it might be just what you are looking for. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=d811

Also, I wouldn't recommend burning bush (euonymous) since it is a very invasive problem for nearby woodlots. There are columnar maples and sweetgum that would fit in the space, but yes, maple, locust and sweetgum all get pretty big, although there are smaller japanese maples that might work, something like paperbark maple. But a lot of the interest of that tree is the peeling bark trunk, which will be lost on you if you plant it outside of the fence. Not lost if you plant it just inside the fence, which is what I would do. I was just going for strong fall color at top of the tree recommendations. Dogwood might also be perfect, it is pretty in the spring and fall. Redbud has a nice week or two in the spring and the rest of the time blah, but again, just my .02, folks love it so YMMV. I planted a prarie fire crab apple at my folks place when they asked for a tree that looked pretty a lot of the time of the year. It has red foliage in spring and fall, bright pink flowers, and then red crab apples that persist for a while. Only looks boring in the dead of winter.

Here's a photo with a crab and paperbark maple in the foreground, up against a fence. This shows why I think the tree should be planted just inside the fence, so you can enjoy all of it. The crab is really old and is to the right, the paperbark is on the left, you can barely make out the peeling bark. Neither tree is doing well because they are planted too close together and are fighting the shade of two very large nearby hemlocks. That's a magnolia in the background, which has too big of a spread for your situation.

I pull invasives out almost every day, I am not "huggy kissy" about natives and plant and enjoy dozens of non-native species, including the lilac, which has also been tagged as mildly invasive. I am surrounded by euonymous and the problems it causes every working day of my life, its not theoretical with me. I am not neutral about it. It is a problem in VA. It's on the US Forest Service's "Most Wanted" list as an invasive species, and its seeds spread by birds, so it travels far away from where it is originally planted. And since it has tons of seeds, they can't be easily contained the way some invasives can, like say cutting the spent flowers off a random butterfly bush in your yard. It's able to overtake the entire understory of many urban woods and crowds out not only the native vegetation, but the native songbirds that depend on them. I cannot in good conscience recommend it, and I can't not mention that it is a troublesome plant, for me and many other land managers. You are free to do as you like, but I'm not going to say "Yay Euonymous." It's pretty much ubiquitous as a landscape planting so one more is insignificant. If Macd lives in the middle of some bustling city, then the euonymous seeds probably won't reach any nearby parks or woodlots where the land managers are trying to hang on to whatever little forest they have left. Here's a story about it in the Chicago Tribune, http://featuresblogs.chicagotribune.com/chicago_gardener/2007/11/whats-wrong-wit.html

It sounds, I-pink, like Euonymus alatus is determined to "become" native after all. Sorry about your plight. I'm not for putting more of it where it is a real problem, but the fact is, once the genie has escaped the bottle, it's likely that it will never be recaptured. Just like Florida will now NEVER be free of Burmese pythons. But evolution and the constant adaptation it requires will never care that we invented the bi-nomial system of nomenclature, formed a country with some agencies and put some plants on list. Evolution, larger than any man or his creations, just doesn't care.

I don't want to hijack this thread and I guess to argue that all human endeavors are pointless and puny given the vast view of evolution is one way of looking at it with finality and who would not cede the point given the awesome "invisible hand" of nature! But even speaking of evolution, it's is not some monster that will roll over the whole world in only one direction, with some foregone conclusion. It only seems that way looking backwards at it. Going forward, it is a plastic, ongoing process made up of millions and millions of events happening millions of times over. While I'm here, I'm going to care for and protect my blip, I can afford to do it, I've got food, water and shelter covered, and the offspring boat has sailed. Also, speaking evolutionarily, sometimes protected pockets of life are the wellspring from which new genes and new life flows, there is danger in genetic uniformity.

These are two photos of my specimen plants, a fireglow japanese maple, and an Ironwood/musclewood tree, Carpinus carolinia. One is native, one is not. These are two I like to look at, but I realize it is not to everyone's taste.

Thank you so much everyone for your input! I didn't know trees could be so controversial :) . I appreciate my newfound knowledge, though.

Anyway, I think I've narrowed it down to a few choices. Any thoughts?

1. Dogwood (either red, kousa, or celestial shadow)

2. Japanese Maple

3. Paperbark Maple

4. Little Gem Magnolia

Many human endeavors are not pointless or puny, but nature has the upper hand.

Carpinus is awesome.

Another lovely possibility is Viburnum prunifolium, a native viburnum, small tree, called here 'Black Haw'.

It's a tough choice because there are so many beautiful trees out there, says the tree loving biologist who works at an arboretum just so I can look at beautiful trees all day and don't have to choose just one! In my own urban yard in PA, which was similar to yours, I hemmed and hawed for over a YEAR trying to pick the perfect tree, since I had room for only a few, and some would argue even less than that. The positive about non-native Kousa dogwood as opposed to the native one, is that it has mottled light bark, which might show up good against your fence. Native dogwood has attractive bark too, but it is very different, it is grey and the bark is rough, or "ruff!" as we tree weenies like to say! Kousa can be grown to have multiple trunks. This weekend I am planting a WEEPING dogwood. Be still my heart, it is so cute. But I have no idea how hardy it is going to get. Another dogwood I forgot to mention is Cornelian dogwood, which goes by the common name "Cornelian Cherry" but it is not a cherry. Scientific name, Cornus mas. Here is one from my arb. It has light, slightly peeling bark and can have multiple trunks. Nice fall color, pretty yellow flowers and druping red berries.

Another magnolia you might consider, is "Butterfly" magnolia, with small yellow blooms. I am planting one this weekend in honor of my mom. Google it and you will find some gorgeous photos. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c164

There are so many wonderful japanese maples to choose from. I'd pick one that has yellow fall color, to contrast with your fence, but that is just my taste. The nice thing about japanese maples is they have great color in both spring and fall, the leaves look gorgeous budding out as well as turning in the fall, and usually lovely forms. There's even a coral bark japanese maple for winter interest. I might try "Autumn Moon" japanese maple in your situation, although they are tougher to grow than my fireglow. Here's a link to Herter's Nursery near you in NC, where I bought mine. You could have a ball on that site trying to pick one. Herter's Nursery

Wow, I thought this would be easy but now I can see myself also deliberating for a year! I've been allowed one tree, so I really need to make it count!
You've definitely all convinced me to plant inside my fence. The only reason I originally thought to do outside was to maintain my limited yard space for my kid to play in. Just not sure how close to the fence I can plant? I'm thinking to plant it in between my door and right side of the fence.
One thing I've noticed googling all these uniquely beautiful trees is some seem to grow like a pyramid and others have a bit more trunk displaying and vegetation at the top. I prefer the latter, since I think it will help me maintain yard space if the majority of the tree is above the fence (eventually). I wasn't sure if these shapes were more a product of pruning/shaping or naturally a certain shape?

As with every living thing, there is built-in genetic code built in that dictates how the form of a thing will be. With plants, the form may be altered by the forces of nature: wind, rain, sun, temperature, nutrition, etc. Also, animals -- especially man -- can alter the form of plants. Usually, a goal of plant selection is to choose a plant whose natural form most closely fits ones vision so that the least amount of altering is necessary. For man, "altering" a plant is work.

After looking through all the recommendations, I decided to go with the rising sun redbud. It seems like an interesting tree.

Anyway, last question: since it is May and the weather is starting to turn to summer in zone 7, is it advisable to wait until fall or spring to plant the tree?

If you can supply water on a regular basis -- according to what the tree needs -- there is no reason you need to wait until fall.