Okra or kohlrabi would be my nominees. Okra is both ugly and beautiful when blooming. Kohlrabi is just plain weird.

So-called fused tomatoes, fruits with severe catfacing can also be quite ugly. And don't forget to consider dragonfruit and horseradish roots.

Dave

Eggplant. The standard black beauty is my favorite, but just about any variety will give you a really unique look.

Here's a cherimoya a Facebook friend just photographed. They are in season right now and apparently delicious.

You can't get more unusual than those little decorative gourds that are sold everywhere in the fall. They come in all different shapes, colors, and textures. Don't know if you want to wait 4-5 months though.

Rodney

Gourds, yes. Most of them are just grown for art purposes. I have grown half a dozen of them in the past, Bottle gourd, birdhouse, swan, snake, various smaller ones.

Another one is a pumpkin called Turk's Turban.
Another: yard long bean.
Another : Chinese Lantern.
Another : Peter Pepper. hehe

A whole stalk of brussel sprouts.

definitely a Mandrake (Mandragora officinarum I think); just look up/google images ...

I nominate kohlrabi, and leeks are beautiful and understated.

For prettiest, I'll go with an artichoke flower! Nancy

Edward Weston is famous for photographing unusual shaped California Peppers.................

Bitter melon (warted fruits)
Martynia (plant, flowers, bizarre seed pods)
Litchi tomato (plant, flowers, fruit)
Jackfruit or durian, if you can find a whole fruit

Martynia would be my best recommendation, the dry pods are really beautiful... and sharp as fish hooks.

My vote is for artichoke!

Don't forget crown-of-thorns gourds.

Check out Tromboncino squash. Easy to grow, and since they are moschata, they are resistant to vine borers. Pretty odd (and very edible).

I'm with zeedman on the durian...

Here is a link that might be useful: Durian