We have also stayed at all 3, and our top pick is the Contemporary. It is worth adding that we usually get a car, and the last few years- prepandemic- if we stayed at a deluxe we often chose club level. As far as I know, for now all the club level lounges are closed. More or less for about $150/night or a little less- club level = a quick and easy continental breakfast, beverages. NO full egg/bacon breakfast, but just about everything else: fruit, cereal, oatmeal, yogurt, breads/muffins/pastries, sometimes hard boiled eggs. Plus snacks and beverages the rest of the day. With 4 people, prices were comparable to eating in the food courts. The real bonus of CL though is that it was a big time saver in the morning.
And that brings me around to why we like the Contemporary so much. Sure, Poly has better theming, but CR= walking to MK, and monorail to all the restaurants on the monorail line. And if that's not enough WL and Ft WL are a short boat ride away.
For me, the Poly rooms were too dark on the inside. The pool is great. It is just so easy to get around when staying at CR - that's CR's real advantage. I happen to think CR's Bay Lake view is one of WDW's big secrets: you get an awesome view of the water parade every night.
GF is also very nice. The rooms are nice and big! And the staff has always been great. The theming and pool are also fun. Bonus: brides/weddings are common! Even if your room doesn't get a great view, the area by the GF's quick serve/marina has a nice view. but that only really matters if WDW has fireworks.
Of all the rooms, GF rooms have a great layout, followed by CR. Poly is a little like CR, but I think CR is better. Well, except for the very odd sinks in the bathroom. They are square, very flat, and don't drain. (always a puddle). The bathroom also lacks counter space, so we end up using one of the sinks as if it was counter space. GF has nice bathrooms. Oh, and the bigger rooms in the main building are really nice, but only if they bring back club level. (All GF main building are normally club level rooms.)
It depends what you want in your hotel.
