First off the article states you don't have to live in places like France or California. So not sure why people wrote in for any place in California here, everyone knows about this state and country.
I'm originally From Bay Ridge Brooklyn, so I have to definitely give a shout to the finger lakes/Ithaca NY region which is in this article. But probably the best region that I've visited outside of California (Sonoma is the best I've visited) has been the Leelanau Peninsula/Traverse City, MI. There wine is world class in this region. It felt like Sonoma there, and there Pinot is some of the best in the world. I've had a chance to visit Williamette Valley, OR as well and likewise great Pinot there. Walla Walla, WA was enjoyable, outstanding wines but i'd put it in 4th behind MI, OR and NY but nonetheless very good and with some wine ratings I know WA is up there. I also had a chance to visit the Central Texas hills region this summer, just north and west of Austin, TX. This is a newer region, but if they continue to plant the right grapes in that dry, volcanic dirt, they will keep getting better and better wines, so I have to disagree with the person from TX who posted on them as any state can have below avg wineries and wine. I also visited Asheville, NC which was good as well, I enjoyed their beer there actually more than their wine, but NC is a good spot to visit. I've also visited Arkansas/Ozarks and Tennessee/Nashville but both of these states were duds actually, they need a lot of help as their wine was just not good to put it nicely. Each region I've visited I've always gone to at least 5-6 wineries to give myself a good overall taste/experience of the region, couldn't get to that many in Arkansas and Tennessee but after the few I tasted, I was ok with that. Used to date a girl in OH, west of Cleveland, decent wine here as well and if your from OH, this is a good spot to do your wine tasting.
I've still yet to visit Virginia which I've heard is very good and had a friend mention MO as enjoyable and she's also from there. And I've only read about Boise, ID. Not sure i'll make it to MO though, but Virginia and Boise are in the works.
So i'm a little shocked all in all that they didin't have Leelanau Peninsula/Traverse City, MI first in this article and the finger lakes region, NY at least 2nd. But I think the people that have visited both of these regions along with Williamette Valley, OR know they are prob the 3 best outside of California. And none of these regions are a secret anymore