I am a bit older than you (already have a 3 as the first number in my age) but I think I have an idea what you are looking for.
I can definitely recommend Kona, it is a very relaxed place, very friendly and welcoming and I thought the food was great!
I know that buffets are a bit more expensive, but I think Boma is a great place to try out and to visit AKL is a bit of an adventure in itself.
When I was in WDW with a friend we ate at Ohana and liked it, it is okay for couples, you do not need to be a family there to feel comfortable, but perhaps it is not the most romantic place to eat at. In the same category I would also suggest Whispering Canyon Cafe which we enjoyed a lot. It is a lot of fun to watch what is going on around you.
We also really liked Wolfgang Puck's Cafe in DTD. I know it gets rather mixed reviews, but we liked it a lot.
Not a tableservice restaurant, but Sunshine Seasons has very good food, too. We found it to be very busy for lunch. We had an early lunch and it started to get very crowded when we left. But we liked it so much that we returned for dinner there and that was much less busy.
Hope this helps a bit!