Well, San Marzanos are supposed to be the official Italian tomato, and Ronde de Nices are supposed to be a traditional French zucchini... My aunt grew a bunch of heirloom tomatoes last year... She liked them, I thought they were okay in the salsa I made with them, but Mom and Grandma Did Not Like. I've been hesitant about any sort of heirlooms since that. lol But I'm going to try to not use hybrids for most of my vegetables next year. Starting from seeds should help me towards that end.

I know of a few seed companies that specialize in heirloom varieties, plus more "standard" seed companies (like Burpee) do include some in their catalogues, in order to appeal to a more varied crowd.