If you have your heart set for taking a wonderful vacation; consider Mexico. It has beautiful beaches, friendly people, delicious tequila & wonderful sunsets.
Let's start with "what kind of traveler are you?"
Cancun is a tourist type of city...very commercial :-)
Nothing wrong with that but you will see high rises everywhere, malls, buses & taxis. But it also has places to rent jet-skies, a lot of nice bars and great restaurants. There's a Bubba Shrimp restaurant, a Ruth Chris Steaks restaurant and even a McDonald's. Cancun has a very vibrant night-life & there's excitement from morning to night!
It feels like a remote oasis away from everything, with it's turquoise water & white pristine sandy beaches; it's very laid-back. No high rises, no buses, no malls everywhere. You can do snorkeling & scuba diving or visit the largest living reef & visit the historical parks or just lay on the beach under a cabana & have a beach butler bring you a drink all day. Riviera Maya has a very relaxing tone & beautiful resorts which are not right next door or seem so crowded like Cancun.