I like rhubarb and strawberry plants in the front. Strawberry is a nice
groundcover, and rhubarb has pretty foilage. I've seen people grow tomatoes
as a border plant. Most herbs are very pretty. I've grown chives & garlic in
my front "flower" bed. Sage is a pretty shrub. Peas growing on a fence or
wire are also very pretty in bloom.

Maybe you should ask what you shouldn't grow in a front yard ;-)

I, personally don't know of any unsightly food plants. If you are creative,
you can make a very fun and pretty display. You could plant spinach in
clumps btween bush beans, and have an alternating display, or something
similar. Along the house, put taller plants in back, gradually getting
shorter as you plant forward. There are so many possibilities!