Thank you everyone for the replies, we have narrowed it down to two… Hawaii or Mexico.
As folks have stated, Mexico is kind of up in the air.
I've travelled a bit and have some 2 cents that may help.
Mexico:
I would avoid Cancun with teenagers. Sure you can stick at the resort and such but you can end up with half naked chicks on the buses, partying down the street, in the hotel, etc. It's just the nature of Cancun craziness that can bust out at anytime anywhere.
A different Mexican vacation destination that is not geared to get everyone hammered and party as their goals 1-3 would serve you better.
I always thought "Cancun is the place couples go if they want to break up" because all they do is fight with all the craziness and chaos of the single people. And this goes for couples of any age range hahaha.
If picking a place in Mexico and if you really want to do a ton of beach stuff, make sure and check that your location has swimming friendly beaches. Many of the beaches are not very swimmable due to rip tides and undercurrents that are things you don't ever want to play around with.
Cozumel is easy to get around and is not crowded with people all over the place. I believe it's known for it's amazing snorkeling and scuba diving. Kids can do snorkeling without ever having done it before where scuba is specialized.
I can't speak to many other places but my brother raves about Los Cabos and Cabo San Lucas but said the beaches are not swimmable and that it cost an arm and a leg at the nice resorts but is an amazing experience.
Cruise:
As for cruises, I just went on my first MSC cruise last month. So here is my take away, and understand that this was a 7 day cruise with 3 stops (Costa Maya Mexico, Roatan Honduras, Cozumel Mexico)
For a family vacation that for people who have done very few vacationing it is a good option.
Lots of activities and places to hit up on the boat for entertainment or for relaxing.
I wouldn't get your hopes up though on the port stops and activities. If you rush you can get off the boat around 8:45am and will be required to be back by 3pm'ish (one stop was 4:15pm).
So that is a mad dash to go do things and get back.
I would suggest you book your port day excursions through the cruise because you will get professional taxying to and from the location and they basically guarantee to get back in time and not screw you over on price or scammy things because they don't dare risk getting blackballed by the cruise ships.
Also have your excursions well thought out and planned and just don't wander into one vs another thinking they will be fantastic. Hedge your bets and pick ones that you can get to easily and are highly touted.
You don't have to book any excursions and can just enjoy the ports which are setup resort style but you will be paying US prices for drinks and food, but not the junk store shopping items. Just haggle with them and know everything is marked up pretty high.
Now for the cruise ship itself.
Pick your room vs having one assigned. We were at the back end of the ship and it was great to be away from all the hustle and bustle that goes on mid ship.
Get a layout of the ship (this can be a little overwhelming at first) and identify rooms that are opposite of high traffic areas and supply closets. This is more noise than you want.
Balcony is worth $100-$150 more compared to non balcony rooms. They are bigger rooms and you can relax with privacy vs the other 3.5k-5.5k hustling around the boat.
MSC makes everyone in a room have the drink package if any person wants the drink package so they can avoid alcohol sharing and fiascos. These are not cheap but worth it if you are a drinker and will be paying for that many drinks anyhow.
I don't drink these days so we avoided the drink packages and it was a little bit of a pain even just getting water to drink.
We took big 40oz mugs and filled up with water at the buffet deck regularly but you make plenty of trips up there to do so as there are no other water filling areas on the boat.
They have non alcoholic drink packages too which I almost broke down and bought for a couple of days but I was able to get into a groove of refilling water AND our scheduled dinner waiter was awesome and was just giving me 1.5 litter bottles of water everyday at dinner.
Yes, on MSC there is the ability to pick a scheduled sit down dinner time and I highly recommend. It cost nothing more and you will get the same table and same waiter every time and they seem happy to hook you up with things to score a big tip. We chose 7pm.
Final Thought
Me personally, I prefer to do a resort location and be able to do things at a resort and out in the area per MY schedule. Also, I prefer the ability to not be tied down in a mass of people all the time unless I choose to be.
I see why cruises though are highly sought after. They are low cost and you can can get them for like $90-125 a day including lodging, gambling, food, boat actives, land stops, etc. They give people an opportunity to get a little bit of everything. Just don't expect a whole lot of one things besides boat activities (trivia, dance lessons, random styles of live music, etc.).
Also if you like a lot of people around and talking with all kinds of strangers and don't mind navigating crowds at various times of the day then the people thing is more a pro than a con for you.
Anyhow, that's my 2 cents.