Have you looked at the discussions, hotel reviews and photos etc on Tripadvisor? Just reading through the numerous posts on the Antalya Province discussion forum will give you loads of information, or you could post your own question as I am sure you will get lots of advice.
I have been to Turkey six times (including to Lykia World twice) and we are returning to the Antalya/Belek region in July and again in October. Personally I think the AI hotels in Turkey represent great value and the DCs love the waterslides and kids facilities and 'free' food. DH and I enjoy happy DCs and 'free' cocktails
I've done a lot of research on the hotels on the Med Coast but obviously it comes down to personal preference versus cost etc. Last year we stayed in the Rixos Premium Hotel in Belek and this year we have booked the Gloria Golf Resort and the Susesi Deluxe Hotel both in Belek. The Gloria Golf is the cheapest of the three - it was refurbished 2/3 years ago and we are staying in a family suite which has two bedrooms and two bathrooms.
Other hotels which get fab reviews for kids facilities are the Royal Wings Hotel in Lara, Royal Dragon Hotel near Side, Cornelia Diamond Hotel in Belek, the Barut Lara, the Limak Lara and the Letoonia Golf Resort. These hotels are all still fairly expensive (although cheaper than Lykia World). There is also a new Lykia World in Antalya which does offer an AI option but like Lykia World in Olu Deniz it is expensive. There are plenty of good cheaper AI options which I haven't listed (Titanic Hotel, Concorde deluxe, Arcadia Hotels, Voyage Belek ... many many more).
In order to get an idea of cost have a look on the Teletext Holidays website or Travel Republic website or, if you prefer, a smaller Travel Agent like Fleetway Travel and check out what is available for your travel dates and the size of your party. Then read the reviews on Tripadvisor and on the Holiday Check website.