Hi Bellatrix,
I've never seen a great answer to that question, especially for us up north, so I started ordering the Northern Special from Sandhill. It is so cheap, and you get at least 2 varieties. I've done this twice now. I realize it is a gamble not knowing what you're getting, and I've received white and red kinds both times. But how bad could a sweet potato be? lol. I also grow them in large pots not in the veggie garden. They are very pretty vines. The foliage really varies between cultivars in color and shape.
I figure when I stumble onto a variety I really love, I'll keep ordering that one along with the special.
You could re-post this question on the Vegetable Forum maybe you'll get a few respondents to list favorites there.
Remy

Hi Bellatrix,

I grow Red Wine Velvet and Brinkley White and am very happy with them. We've also grown Maryland 810 and Georgia Red. Both were very nice. An heirloom, which I believe is from the PA area originally is Pumpkin. I hear that it produces a good crop of roots concentrated right under the plant. I may yet try that one.

Remy's suggestion is also very good. We got all but Red Wine Velvet from Sandhill through one of their specials. None have disappointed us. I am convinced that the folks at Sandhill often actually think about their customers (where they live and what they might like) when they fill orders.

George
Tahlequah, OK