This is tough because everyone's preferences are different. We have stayed at all 4 resorts that you're considering. I can give you my thoughts on each, but in the end...what's right for us may not be right for you.
Contemporary - This is my favorite. I think it is the most convenient of all of the WDW resorts. You can walk to and from MK, you are 1 stop on the monorail from the TTC - so it's super quick/easy to transfer to the Epcot line, you're on the resort loop- so any dining at the Poly or GF is super easy, and you have boat access to WL and Ft Wilderness. The rooms are also very spacious. While staying in the towers is a bit more convenient and a theme park view gives you that amazing perk of watching Wishes from your balcony, you also have the Garden Wing which is arguably one of the best values (from a deluxe mindset) on property. The rooms in the GW are the same size as the tower rooms, decorated the same too, and IMO a VERY EASY walk to the tower. Contemporary is also the best place to be if you want a 7am ADR at Chef Mickey's since you don't have to worry about cabs or grabbing the earliest bus.
Poly - I know many people on here LOVE the Poly, so let me state for the record that I'm just not a Poly person. The theme does nothing for me. It's a pretty resort, but I don't like the longhouses being separate from GCH. You can walk to the TTC from the Poly, but I still think the monorail from the Contemporary to the TTC is easier. The boat access to MK is great, the beach (at least pre-construction) was my fave, and of course- you're on the monorail line- so that's awesome convenience. The room decor is not my thing, but they are very spacious well appointed rooms. Once construction is done, assuming they don't mess with things too much, I'd say this is the best pool of the 4.
Wilderness Lodge - Another one that I know many LOVE, but I really did not like staying at WL. The common areas are neat, but I hated the room. The room felt dark and cramped. I also felt a woods view was a joke. I know you're supposed to feel like you're out in the wild and transported to a place other than WDW, but it never felt that way to me. Maybe it's that I could make out the castle and the Contemporary through the trees, but I was disappointed. We even stayed during the holidays and the big tree in the lobby wasn't enough to sway me. It also didn't help that the bus service at WL was downright disgraceful during our stay. The boat service was good, but we've had issues on multiple trips with it not always running. When we stayed there, they suspended some of the early boats due to cold weather. During a summer trip, we couldn't make it over there because the boats couldn't operate with lightning. Understandable, but frustrating since it felt like bus service to MK was really spotty due to the boat service.
Animal Kingdom Lodge - I was nervous staying here because of how I felt about WL. I mean, they are similar in design and the rooms are the same size. I was shocked at how much I loved AKL. I liked the common areas even better than WL and the rooms felt so much brighter. Obviously, having animals off of the balcony is a big help and it really did make you feel like you were someplace other than WDW. The CMs at AKL were wonderful, I loved being able to walk to Sanaa over at Kidani, the kids really enjoyed the zero entry pool, and while it's a longer bus drive...it's some of the best bus service we've had at WDW. We also were given savanna options at 60-day check in for room preferences, yet we were not booked in a savanna view room. So, that was very awesome. The only real issue...and it's an issue we had at WL as well...was the beds. I know they are all queens, but I swear...the ones at the Contemporary and the Poly were so much more comfortable.
So, now that I'm done with my mini novel
LOL - I rank Contemporary first and AKL second.
