@immig4us
Hope you have been doing good buddy! I am sure your IL should be on it's way soon. The IL they send does contain a list of all the documents they expect in the interview, but that is not the finite list. Usually they mention the originals of all the supporting documents you submitted along with your AOS package (birth certificates for both of you, driver's license, proof of citizenship, passports, employer letter, W2, 1040, all kinds of immigration documents that you have ever since you entered the US etc). Apart from this people do carry proof of living together - which includes and not limited to joint account documents, life and health insurance copies, least/joint home ownership proof, proof of any other property you have together, car's joint-ownership, pictures, car insurance copies and the list can go on. Basically the more proofs you have the better your case is. We were even asked if we have the same keys to our home. Luckily I had read about that the morning of our interview and I asked my wife to specifically carry her set of keys with her to the interview because whenever we go out together, she leaves her keys back home. The interviewer didn't ask to see both the keys but it's good to have everything rather than going back to submit the proofs. So yes, go through your pile of mails for the past months and pick up all the letters, joint statements, insurance card you have received. I did not carry tons and tons of documents but did carry some significant ones. They were never asked for but they are all nice to have sort of documents.
Hope this helps.