Berries are good choices. A few years back some of the WSers were sowing the seeds they removed from cranberries but I don't remember their extraction process, maybe someone will chime in with experience or memory.

Swallowtail Garden has seeds of Alpine Strawberries, I'll paste in a link for them.

You can WS many grocery fruit seeds though most are likely unstable hybrids or are well known to not produce similar fruits, as an example you will get apple trees from the seeds you take from an apple but the offspring will not be all the same. It's like the children of one couple, sometimes the children are all very similar or sometimes the children take after their different grandparents and you see a combination of the different facial and physical traits mixed up among all the children.

I do think apples are a still a very good choice for Winter Sowing because you are growing hardwood trees which add value to your property, you will get edible fruits--some may be more appropriate for applesauce than fresh eating but apples they will be, and also very important, hardwood trees do flower and provide pollen and nectar for bees, and they also provide shelter for perching birds.

Here is a link that might be useful: Alpine Strawberries from Swallowtail Garden

The only fruit I've wintersown has been Flowering Quince (winter 2005) and I'm not sure how long before flowering/fruiting begins.

I am attempting winter sowing with Giant Cape Gooseberries this year. I cannot attest whether I will be successful. I may end up babying the seedlings by covering or bringing inside during freezes, and sow some indoor as well for back ups. I will report my results. The cool thing about this berry is, if all goes well, I will be able to eat fruit this year. It is an annual in my zone though, as it can't survive the winters here.

Here is a link that might be useful: Gooseberry Seeds

The nursery I went to yesterday had alpine strawberry seeds (unknown variety) on their Livingston seed rack for $1.89
I just WS'd it now.

I wintersowed alpine strawberries last year and they did great. They are tough little plants! I even got berries from them the first year (which I wasn't really expecting).

Lois in PA

I winter sowed some apple seeds that came from a golden apple and 3 peach seeds that came from these cute little plants about 2 1/2 feet tall with burgandy foliage this year. I dont know what those peach plants were called? cant wait to see if they come up. I did 5 Japanese Maple seeds also that I received from Token.

I have hardy orange ,edible quence, blackberry,goji berry white pomegranate persimmon,and a few others
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that haven't sprouted yet
Kiddo,,,