I personally think its best to pick the hotel you like best rather than base it on which CL is "better" since they are fairly identical in terms of services offered but here's what I think about each.
GF offers a bit more food (an actual afternoon tea instead of chips and such) but I'm not a fan of the fact that there are two levels of CL service (Poly and CR technically have two CL's but for each, one is mainly the floor/building with the suites and one is the one with regular rooms) because it makes the more desirable one prohibitively expensive. The cheaper CL building is Sugar Loaf and that is outside the main building. The services are pretty identical to the Royal Palm Club in the main building, but the lounge is in a high traffic area of the lobby and not as "relaxing" as the RPC or other CL's.
The views from GF CL rooms and the lounges themselves are probably the worst of the bunch. Poly has a dead on view of the MK, albeit across the lagoon, and the CR feels like its right on top of the MK, albeit with a parking lot view as well. Even if you don't book a park view room at the Poly/CR the lounges at both have great views and pipe in Wishes music. The theme park view rooms at GF are at an odd angle and aren't quite as nice as the other two. I could be wrong, but I don't think either lounge has much of a view to speak of (sure about Sugar Loaf, but not about RPC). So if you stay at GF and want to have a view of the MK, you probably have to pay for the view in your room instead of being able to save a little bit and take advantage of the lounge.
Aside from that, the food offerings vary slightly due to the themes of the resorts (Poly typically has more pan-Asian offerings than the CR/GF) and the decor pretty much matches that of the hotels themselves.
Personally I would probably rank the GF last since even the Sugar Loaf building is the most expensive of the group and the RPC starts at about $100-200 more per night than that. Sure you get a bit more food, but I like the setups at the Poly and the CR better.