We really just can’t get enough travel. :). I feel more comfortable (and interested) in domestic places.
Someone is going to visit your state. Pretend they like all kinds of sightseeing/nature, etc. You have to highlight 3 and ONLY 3 cities or places they should visit.
What 3 are you suggesting for them? List your state first and then the cities/places - and why if you like.
If you don’t live in the 
, use your country or province or whatever is comparable to a state.
Ohio
Hocking Hills (central Ohio) for hiking and nature. A real outdoor gem and the terrain is unlike most of Ohio.
Columbus (great food, unique neighborhoods, vibrant areas, art and entertainment)
Cleveland (visit the lake towns, GREAT food, again, really cool neighborhoods, just an a great do-able urban vibe. Beautiful parks and ethnic areas to visit).
Tennessee
Franklin for History and charm and restaurants with access to hiking
Gatlinburg-ish area for the Great Smoky Mountain National Park
Memphis for its downtown music scene ( or Nashville for the same (but more country music)
Connecticut
Mystic - quaint shoreline town, nice shops, excellent restaurants, Mystic Village, Mystic Aquarium
New Haven - fun city, great museums, Yale, pizza!
Lake Waramaug area - quaint towns, winery, state park, hiking, kayaking
Don’t forget all the terrific museums, and the Rock and Roll Hall of Fame. Must do places when visiting Cleveland. In the summer, head out to Blossom Music Center for a concert (summer home of the Cleveland Orchestra but also other concerts too). And check out the fabulous arts programming at Cain Park in Cleveland Heights.
Tried to keep my mentions to just a couple things - and stand out things that I would do! 
Michigan
Sleeping Bear Dunes
Mackinac island
So many for the 3rd!
Saugatuck, just a default! Because it’s really hard to pick just 3
Michigan also:
Leelanau peninsula- stay in a house or cottage directly on Lake Michigan and enjoy whatever water sport you enjoy, kayaking, fishing, swimming. Bicycle the rails to trails bike trail that goes by Sleeping Bear Sand Dunes, explore beach towns- Leland, Northport, Sutton’s Bay
Detroit- DIA, Henry Ford museum, Motown museum, side trip to Ann Arbor
Petoskey/ Charlevoix area
(Can you tell where my favorite place is?)
lol it’s possible that is REALLY pushing 3 places.
I may have to penalize you but since it’s Michigan….
For Hawaii, we have Iolani Palace, the only royal palace in the US that housed monarchs on Oahu.
On Kauai, we have Waimea Canyon that is gorgeous.
On the Big Island we currently have erupting Kīlauea.
Of course we have sooo much more!
Washington (please don’t say “state” 
):
Mount Rainier NP
Olympic Peninsula
Whidbey Island
Illinois-
Shawnee National Forest- beautiful and underpopulated
Cahokia Mounds- World Heritage Site
And of course, Chicago
I don’t know Whidbey Island!!!
Haha! Sorry
I was thinking about Washington and came up with Mt Rainier, Olympic National Park, and Seattle.
The fun of this is that we all have different views of “must see”. My “must see’s” will be based a lot on outside activities, food scene, walking neighborhoods. Another person in my state might highlight museums - which are not something I value as much!
California - only three?! (Technically Disney Land is the #1 attraction but I would never list it.)
San Diego - still love it after 10 years and so many things to do within a day’s reach.
Big Sur and Monterey - beautiful drives.
And because I just got back, and because it’s spectacular, Yosemite.
But there are so many more that could easily make the list.
To be honest I kept it at three because I didn’t want it to turn into a bragging thread. Which CC often becomes. People do like to play the “I’ll top that!” Game.
I think any of us could list more - even boring old Ohio has more highlights than 3 - but sometimes it’s good to have to make decisions.
New Mexico
Santa Fe–history & culture, art & opera, great food, beautiful mountains
Taos-- Taos Pueblo, Old Town, Rio Grande Gorge, Mt Wheeler
Silver City-- where Billy the Kid grew up, vibrant arts scene, mountain and road biking, close to Gila Cliff Dwellings and Gila Wilderness (Walking the Catwalk is a must–though the USFS has replace a lot of the old questionably suspended portions with modern bridges and cantilevered walkways which makes it less of an “adventure” than it used to be.)
New York
NYC
a. top of one tall building (e.g., Empire State Building, Top of the Rock, World Trade Center, etc.)
b. Brooklyn Heights including Promenade and Brooklyn Bridge Park
c. Circle Line boat ride around Manhattan
Ithaca
a. Cornell campus including botanical garden
b. Buttermilk Falls State Park
c. Cascadilla gorge trail
Buffalo/Niagara Falls
a. the falls (duh!). Best views across the border in Canada
b. Frank Lloyd Wright’s Martin House
c. Canalside
(I confess that much of the Buffalo stuff is from Google–you too can search! It’s been a while since I was there.)