You could replant horse radish, peaches, cherries, raspberries and strawberries from the seeds, raw peanuts, ginger, and lemons and oranges can also be grown from the seeds. Keep in mind you will not get the original hybrid from seeds

Most of the tomatoes at the grocery store are not worth growing, the exception are the grape tomatoes, which, although hybrids, I hear grow out pretty close to the parents and taste much better home grown. If you can find Jeruselem artichokes = sunchokes they should grow from the tubers (look like ginger, taste like sweet jicima).

Onions will not grow into anything edible, and even if you grew them out to set seed, growing onions from seed is a pain. I don't think you could get celery to root, and if you did, you couldn't do anything with it.

Pineapple is a fun plant to grow, but you can't do much with it. Cut the top off, strip some of the lower leaves, set in water and then plant when roots sprout.

Avacado seeds will sprout

Melon and winter squash seeds

Bird seed/ sunflower seeds

Dried beans...

Lots and lots and lots . . .

Here is a link that might be useful: Plant from the produce department?

Peppers - green , yellow , red - sweet or hot - do really well from seed .
Try planting the green onion bottoms - the white part with roots . Then continue cutting the green shoots as they grow all summer .

I have been successful with planting old potato into the garden from the grocery store. I saved the seeds from squash and planted that and have a lot of squash growing. I have planted garlic from when the garlic cloves are starting to get a little old, and now I have a nice big ongoing patch of garlic in my yard. Here is one you might be surprised by... When I cut the root end off of scallions I cut it so there is about an inch of scallion with the roots still on them and plant that in the garden and I end up with new scallions growing from it.

Basically, anything with a seed in it can be harvested like melons too. When we were kids we would save carrot tops and plant those, but I don't remember how well the carrots did (it was a very long time ago)

packaged dried whole peppers often yield good seed.

Dill and fennel will grow in the garden. They re-seed themselves prolifically. Added bonus: they are food plants for swallowtail butterflies.

I have bought different heirloom tomatoes and tried them. If I like the flavor, I save the seeds and grow my own plants or use the seeds for trades. I have grown the mini sweet red, yellow and orange peppers. I save the seeds from winter squash and grow them. I have planted ginger tubers and Jerusalem artichokes. When potatoes grow eyes I plant them. I also have planted shallots and garlic.
Clare