Hi Flowers:
I have had WS success with perennial varieties of thyme, sage, parsley, and oregano (although I guess they are herbs). Also with lettuce and green bunching onions. It's hit or miss for me so far north with tomatoes, so I still start them and peppers indoors. Everything else I direct sow early in the season (cucumbers, squash,okra, swiss chard, beans). You may have more choice in your more southerly zone.
Northerner.

Like northerner, I have only wintersown hardy perennial herbs. As for veggies I have early spring sown cool season and later spring sown warm season veggies :D
This was my first year to have w'sown tomatoes and they actually did great. Also tried Thai Hot peppers...only difference between starting them indoors like I usually do and wintersowing is that I only got one harvest instead of two, but Thai's are heavy producers so one crop is awesome never-the-less :D
Still started the rest of my peppers (Habs, Barney and Pueblo) indoors, but next year might try wintersowing the last two, but Habs NEVER.

Vera

Last year was my first year to wintersow, AND my first veggie garden, so I'm not an expert on this, but here is what I winter/spring sowed.

Lettuce (mid-April)- great germination rate
Spinach (mid-April)- also high germination rate
Swiss Chard (mid-April) - good germ. and seedling survival rate
Dill (February) - germ. okay, but lost some to ? wilt
Cilantro (February) - good germ., lost most after planting out
Basil (late March) - germ. fair, never grew well this year
Parsley (March) - good germ., good survival
Marjoram (Feb.) - good germ., lost most after planting out
Oregano (Feb.) - good germ., good survival rate
Spearmint (Feb.) - germ. good, but died after planting out ... yea, I am that one person that CAN kill mint, LOL
Thyme (Feb.) - germ. good, survival rate good
Peppers (April & May) - poor germ., lost most that germ. to ? wilt
Onion (April) - germ. okay, but then they all died of ?, had better luck direct sowing these

Other things I direct sowed were carrots, beans, pumpkins, and cucumbers.

I say try it with a few seeds, you can always save some to direct sow later if it doesn't work. I had plenty of seeds left over after wintersowing, so it doesn't cost anything to try it, except some potting soil.

Bonnie

I like to try different things.
I have WSed several of my veggies for the last 2 years and even with the greenhouse this year, I will do it again.
I must say I only got about a 35% success rate this year due to all the heavy rains day after day. I was not at home when they started and lost many of my seedlings.
The year before I averaged about 65 to 70%.
Two things I did that I feel helped me along: I read about veggies in these forums and I over sewed my seeds.

Seeds I WSed with success over the past 2 years:
Zucchini
Onions
watermellon
peas
beans
lettuce
tomatoes
cabbage
broccoli
cantalope
peppers
cucumbers
basil
cilantro

I have already started my plans for 2008. I have saved many of the seeds from the veggies (which came from the ones that survived the year before) to WS and I have planted some of them in my greenhouse. I am also looking to purchase open-polinated or heirloom seeds. I hope it will make a difference.

Please know that I am a beginner and I can only tell you what I have done. I love trial and error.

cristi

watermelon and cantaloupe did ok for you Joy?

I guess I may as well try WSing those too. I have Hales Best and Sugar Baby. I'll WS 1/2 and grow the other half indoors under lights later as a backup.

The veggies I remember winter sowing off the top of my head are:

lettuce
spinach
swiss chard
tomatoes
kohlrabi

All of these did really well for me.