Where do grown-ups go on a summer vacation?

Nthing ilikemthisway's suggestion, though I'm sorta biased given that I'm the fiancé mentioned there. A couple of caveats with the Michigan suggestion is that I don't think you're going to get the great food up in the UP for the most part... though there might be parts. You'll also deal with crowds if you're on the island. Meanwhile, I'm in the middle of planning our honeymoon, and I think this thread may have saved me a question. :)

Seconding the obscure recommendation for Oregon's Willamette Valley. I grew up there. It's beautiful, there's tons of wine, there's tons of hiking, and you can easily drive to the coast or the mountains for more varied terrain and outdoor activities. If you like beer, stay in Portland for a few days while you're at it. You can fly into Portland, drive down I-5 to Salem and environs for wine country, head west to the coast for a few days, then drive up the coast, visit beautiful Astoria, and drive east to Portland for your flight. That was my last trip home and it was fantastic. Lots of driving, but lots of different things to see and do. Definitely never boring. (when my husband and I have vacation time, I lobby for Oregon every time. I'm biased. But every trip has been awesome, even the time we got snowed in over Christmas. We ventured out to see the Spruce Goose in McMinnville, we went to the coast to look at snow on the beach and sea lions in Newport harbor, we ate wonderful fresh smoked salmon, and we would have gone to the Rogue Brewery if it would have been open. All within easy driving distance of my parents' house in the central valley.)

http://www.banfflakelouise.com/Places-to-Stay/Bed-Breakfast please take me with you!

Oops, forgot that you can also fly from Chicago into the Toronto Islands airport via https://www1.flyporter.com/Flight/Tickets?culture=en-US, in case that works better for whatever reason. Porter also flys from Chicago to Montreal and Quebec City. Taking this opportunity to say that http://ask.metafilter.com/232721/Where-do-grownups-go-on-a-summer-vacation#3369261 and http://ask.metafilter.com/232721/Where-do-grownups-go-on-a-summer-vacation#3369276 are spot on with the Banff recommendation too. (They don't have as much wine as Ontario or BC, but it is so so beautiful in the mountains.)

If you're in Chicago, why not look at the Upper Peninsula in Michigan? You won't even need to fly there, and can save the air fare to upgrade your room to a comfier king size bed or a room with a better view. Or just spend the week on Mackinac Island. It's absolutely beautiful scenery and like taking a step back in time, in a good-for-the-soul, breath-of-fresh-air relaxing sort of way. Last summer, my fiancé and I did a road trip through the UP and it was delightful and a nice break. We stayed in a few light houses even, and stopped at others, visited random attractions (we pet a bear cub!), and did short walks to waterfalls and along random beaches to enjoy the waterfront scenery. In you want to go farther away from home to a less packed place, look at Asheville / the Smoky Mountains / The Blue Ridge Parkway. A few years back, we did a road trip hitting all three (Gatlinburg, to Asheville, then up through VA/WV), and it was also very enjoyable and laid back. Lots of nature for hiking, and plenty of other attractions for grown ups. (We spent two days at Biltmore and didn't see the entire property! We did get to tour the winery and sample the wares.) I'd totally go on either trip again.

...we'll be flying out of Chicago and are looking to stay in North America. If you could stretch your area to include Mexico, I would sincerely recommend staying at http://www.verana.com/site/php/landingpages.php?pagenumber=0301&language=english. I always recommend this place to couples for a quiet, off-the-beaten-path anniversary trip.

Nthing Seattle for 3-4 days plus somewhere in the mountains or the Sound for 3-4 days. You could head to the Olympic Peninsula for snow-capped mountains, beaches AND rainforest (it's magical, seriously); the San Juan Islands for whale-watching, kayaking and hiking (and maybe spend a day on the way in the Skagit Valley which is delightful); or the North Cascades for hiking in Alps-like mountains and cute little old Western towns. All of these have nice places to stay though you'll want to book early, especially on the Peninsula. The food in Seattle is great. There's less good food in the areas outside the city but you do get lots of fresh produce and fish, and it's getting better. But there's seriously nothing like hiking in Washington in the summer. If you come after the 4th of July, you're almost guaranteed perfect weather: sunny and high 70s during the day, cool at night, no humidity. Even the occasional heat wave is manageable because it doesn't get humid.

Northern Michigan would be high on my list, too. But I'll never disclose my favorite spots in a public forum.

I'm nthing the unholy Portland-Seattle-Vancouver, BC trifecta. All three are beautiful cities, with their own quirks and quarks. Plus, if you fly into Seattle, you are equidistant between both Portland and Vancouver, BC. So when you want to go to the next city, you're only 3-4 hours away. Both the Amtrak Cascades and the Bolt Bus can get you to both destinations quickly, have reasonable prices, and some absolutely stunning scenery along the way.