Well I have no idea what your climate is, but you can change that. As you can see, I'm in zone 6a in Southeast Michigan. I have spent more money on edibles than ornamentals, but that is just a matter of time. Eventually you will too.
I have both sun and shade areas, so I need both.
For shade as a specimen plant the Tri-color beech is fantastic. This is really more an ornamental even though it can produce edible nuts. Best to have other beeches around, and my Purple beeches died, so I do not at the moment.

I formed a hedge with Cornus Mas, and also a double hedge with elderberry in the back and Currants in the front. This is a semi-shaded area too. I used Black Lace, Black Beauty, two American elders Wyldwood, and Bob Gordon for fruit production. Also added two different variegated elders as they are most beautiful. And the yellow fruited elder. So 7 elders 6 feet apart, Six feet in front of the elders are white, pink, and red currants. I also added 3 gooseberries a blue, red, and yellow cultivars. 4 feet apart, total of 8 plants. 2 red, 2 pink, 1 white currants.
All these projects are new so plants are small, and nothing to look at at the moment.
Near the tri-color beech I added a clumping bamboo hardy in my zone. I don't think shoots are edible, but they may be?
For fall color I added as a specimen tree the serviceberry Autumn Bliss, I also added Northline for fruit.

I would also like to make a hedge of filberts, but not sure where I can put it? I opted for the elder and currants as it is probably too shady there for filberts, and I would rather have berries. But I still like the idea of a 12 tall filbert hedge.
Here is a photo of a Cornus Mas hedge. Mine are still seedlings, 2 years in ground.

Here is a close up of the Cornus Mas where you can see the berries (still green)

Here is a photo of a vareigated elder. Mine is still a seedling. Sambucus nigra 'Pulverulenta'

Here in the city I'm growing an Eastern Prince Magnolia vine. The leaves and berries are edible, I'm also forming two red currant cordons on my fence. Again all are still very small. I would like to espalier some trees too, they look very cool. But have yet to start any.

Looks pretty cool so far Drew!

I'm in a completely different climate than you, though still the same hardiness zone. So far, the plants I've put in that seem to double as ornamentals and edibles are: Golden Currant, Elder (Mexicana and Canadensis), Sand Cherry, Seaberry, Grape, Apricot, Apple, New Mexico Locust (edible flowers), Peach.

Lots more in the ground, but still too small to tell which will be worthy of the term "ornamental". In my mind the most important thing an "ornamental" plant has to do is thrive to look beautiful. This can be more challenging in parts of the arid West, such as where I live, especially given the three-year drought we're in right now. Maybe I'll post some pics if this thread generates some more interest.

Yes some very nice peach trees around. Large flowers, purple colored leaves etc. I have a Nectaplum with purple flowers and deep red/purple leaves that slowly turn green.I would like to grow the American currant too, and other related berry bushes. I have wanted to grow some sand cherry x plum crosses. But have not found any for sale. They used to be popular, and are sill sold in Canada.
Blueberries can be used as hedges too, and are nice looking plants.
I'm really looking forward to my plants maturing and looking better. At this point they are not much to look at. I'll do my best to keep them going. This is subject matter that really interests me, thanks for bringing it up.
Here is a photo of the tri-color beech leaves. Mine has like 6 leaves! I'm just hoping the dog doesn't step on it!

This post was edited by Drew51 on Tue, Jun 4, 13 at 15:32

Here is mine, quite small, hard to obtain. It requires shade, else leaves will burn badly. Where I have it it only get's morning sun. Speaking of small plants my Autumn Bliss had 4 main branches. it looked nice for a small tree. I accidently stepped on it, and broke off 3 branches. Now it looks a lot like this one with green leaves at present.

You guys are going to hate me for suggesting this, but i would say russian olive.

Now, take away the fact that down south it is horribly invasive. You can pollard them and use the branches and laves as mulch, the flowers attract all kinds of pollinators (and smell wicked). They dont get massively tall, yet still can provide some good shade, dappled light, or even trimmed for maximum light on the ground. They add nitrogen to the soil, and can take some crazy abuse, therefore making able to "nurse" less tough trees until they get large enough to be able to handle harsh conditions, The wood is also very dense and is amazing firewood.

Personally, as long as the trees are functional in some way (aside from the obvious) I welcome them. The only tree that I have that wouldnt be thought of as "usefull" is a Ginkgo. I love history, and had a facination with dinosaurs as a kid, so this living fossil is perfect for me.

The other thing is, you can get a flowering/ornamental pear, ornamental cherries and crab apple trees, and graft edible branches on them, making "useless" trees functional.

To be fair, shade trees would be useful in some places, making you able to grow some plants that wouldnt be able to grow in full sun (climates like arizona). I couldnt imagine growing tomatoes in full sun all day in australia for instance, without lots of water.

Some other double duty plants I can think of are grapes, nausturium, linden (edible new leaves), ostrich ferns (fiddleheads), mushrooms (break down wood, builds soil, and you can eat them if you cultivate the right ones), roses, alder, locusts, redbuds, acacia, any legume family tree, walnuts (ive seen people use them in spots to discourage almost all plant growth where they didnt want any, almost like using the problem of jugalans to their advantage), maxamillion sunflower, passiflora.....

I think the Autumn Olive, Silverberry, and Goumi are excellent plants. I don't have any, but certainly would consider them. Buffaloberry too. I have though run out of room. Edible plants are all over my property!

This post was edited by Drew51 on Thu, Jun 6, 13 at 9:53

The Elaeagnaceae rocks!

Russian Olive is a big problem here in NM, and as far as I know all up through the interior West into Canada. Some of the healthiest-looking RO groves I've ever seen were in Montana, just a stone's through from the Canada border, so I would not say that it is only a problem "down south".

But, I also love the plant for many of the reasons already mentioned, and am currently trialing it as a rootstock for Goumi, Autumn Olive, and Seaberry (different genus though).

For me citrus is the edible ornamental champion. They are evergreen with fragrant flowers in spring and tasty fruit through out the year (if you plant for holding ability and successive ripening). Citrus is also an easy care plant in my locale, for the most part.

Figs are a close second as they impart a some what tropical look and bear fruit as early as May (with a breba crop) and all the way to frost.

Wonderful pomegranate gets honorable mention as they are stunning in bloom and the fruit is excellent.

I definitely second citrus. I grow lemons, oranges, grapefruit, limes, and a few more unusual type.
One of my very favorite double-duty plant is kiwi (Actinidia deliciosa), because of its huge round leaves, red stems, and pretty flowers, and the fruit is one of my favorites. The down sides to kiwis are their monstrous growth habit, and the fact that they are water hogs.
I mitigate these downfalls by: growing them on a huge pergola, so they will eventually pride shade for the deck below, and by using my graywater system to water them, so I don't feel guilty about wasting water on them. (I use graywater for just about everything).

Alas, I am not in such a favored climate as the last two posters! An arid zone 6 does not offer so many interesting possibilities I'm afraid. I agree that citrus are beautiful trees.

I'm on my second trial of hardy kiwi though. So far seems to need too much water for where I am, and can't hack the late freezes either. I'll keep this male and female pair until the bitter end though, if it comes to that.

I really do wish I could find a fast-growing fruiting vine for my area. Even grapes are taking too long to bear and not providing the rampant growth I expected. I'm still hoping that hardy passion flower (P. incarnata) could be a good tough perennial vine that could also bear fruit. I've yet to get one established however.