LYFMB I know the hotels in the Antalya area quite well as we have been to Turkey many times and I have spent quite some time over the years reading the reviews for each hotel. I also have several friends who have stayed in some of the hotels that I haven't! Alanya is a long way east from Antalya.
The area is awash with 5* hotels but you will see by the prices that some are more expensive than others ... and this is for a reason. I know it is obvious to say but the more you pay, the more high end the hotel and facilities.
I will list a few hotels where my friends or I have stayed (with children) that we would recommend:
Voyage Belek (a very good slightly less expensive option with great entertainment for kids)
Susesi Belek
Gloria Golf hotel Belek
Rixos Premium Belek
Cornelia Diamond Belek
Delphin Imperial Lara newly opened this year(I've stayed there too cappucinogirl)
Delphin Diva Lara (cheaper than the Imperial and next door)
Sherwood Dreams
Royal Holiday Palace
Royal Dragon Colakli (near Side)
Paloma Oceana Colakli
Royal Alhambra Palace
Gural Premier Tekirova (a personal favourite of mine but quite a long transfer from airport). Tekirova is a much more scenic area than Lrar and Belek and is west of Antalya.
Also worth considering and popular on mumsnet is Lykia World Resort in Olu Deniz (I have been twice but not for a few years now) and also the Hilton Dalaman
About the areas: Lara is a 20 minute transfer from Antaya airport so easy to hop in a taxi and spend a day or evening in Antalya town. All the hotels are side by side along the beachfront and there are a couple of shopping malls but nothing to get excited about.
The hotels in Belek are much more spread out and tend to have wider beachfront locations and more spacious grounds. There are some that are built side by side but the Rixos Premium and the Gloria Golf, Gloria Serenity and Gloria Verde hotels, for example, are set on very spacious plots. Some are within walking distance of Belek town (which is inland).
Colakli is near Side so you could visit from there by bus or taxi.
I hope that helps to start with! 