I would pick DCL without any hesitation. As I get older, I enjoy the ambiance of the parks, but the rides are becoming less and less entertaining. I still love a day in the parks with my teenagers, but there is something near perfect about cruising for us.
I love that I am disconnected from work and the world (and hope Disney never offers better internet access). I love the small amount of planning that goes into a cruise versus WDW. I love the low-effort cruising takes once you walk on the ship. I love that there is food to fit everyone's tastes at every meal (my 14 year old had two cheeseburgers for dinner most nights, while I enjoyed seabass). I love not trekking into the parks and out every day. I love the feeling of not trying to pack the day with plans from morning until late night so that we don't miss anything in one of the parks. I love the feeling that I am not wasting vacation time when there is a sea day, because it is designed to do very little. I love the ocean breeze and warm sun. I love sitting in the Walt Disney Theater at night with my entire family by my side, nobody arguing that they are missing out on the thing they wanted to do. I love that the family can split up in a safe environment. If my wife is tired, she can be in the room resting in minutes, while I can sit out on the deck with my daughter enjoying the sunshine. I love the feeling of having paid for nearly everything up front and not being concerned about whether I am staying on budget all week. I love not spending most of each day standing in lines. I love the motion of the ship while sleeping at night. I love that my social daughter can make friends in the Vibe, and my reserved daughter can hang with us. I love the view from Cabanas for lunch. I love that most people on the ship wear smiles and are polite, versus a good dose of over-stressed parents and grumpy faces at the park (not everyone, but it seems fairly prevalent, and I have been that dad at times when the kids were young despite my best efforts). I love Castaway Cay, which is an amazing beach without many of the discomforts some days at the beach require. I love the gentle Disney music as you walk the halls of the ship. I love the way the outdoor decks look, all clean and ship-shape (odd, I know). I love the solid state room and bathroom doors (again, odd, I know). Speaking of that, I love the public bathrooms on the ship (even better and cleaner than the parks). I love waking up and seeing a new place outside. I love the cozy feeling of the entire family in that small stateroom at night, watching a classic Disney movie. Even with teenagers, there is something really comforting about it.
There is so much of DCL that hits all the right notes for me. Some vacations are more interesting, educational, or even "fun" at times, but DCL is still my top pick.