I have several, but here are a few (and there are more on my bucket list as well):
Turner Falls, Oklahoma: It's a wonderful camping area when it's not too crowded...that is why I usually camp there off-season
Hanauma Bay (On Oahu), Hawaii: Really, there are a lot of attractions on Oahu, but Hanauma Bay is prob my fav one there. Wonderful snorkeling.
Colorado (too many interesting places in the state to list here, really, but I'll post a good attraction)
Centro Astronómico Alfa Aldea – Vicuña, Chile: The astronomy in this part of Chile is astounding. There are a lot of interesting places to visit in the area and the landscape is beautiful, but the main attraction is the astronomy.
Myles Standish State Forest- Plymouth, Ma: This is a gorgeous, peaceful place to spend time and exploring historic parts Plymouth is close enough visit too.
Cancun, Mexico: Cancun itself is alright I guess, but it's the attractions near that are great. Chichen Itza, Cozumel, Isla Mujeres