One of the interesting things about my BFF is that her hubby and mine get along great, and I get along great with her hubby and she gets along great with mine. So every combination works, which is really nice for vacationing together. Also, she works unGodly hours in the summer, so we basically don't see each other or talk for the whole summer and once that is over it is like we just saw each other yesterday. The funny thing is that her personality is very like my DH and my personality is very similar to her DH so we tend to be the voice of reason when one of us is complaining about the hubs. We also have a rule that basically we are not allowed to think less of the others spouse after a tirade. We know that there will be no divorce, and that it is just a rant. This works really well to keep things fun when we all get together!
I think she doesn't think about the stuff they do for us, partially because it is mostly her DH that does the stuff and she probably doesn't know about half of it. He is crafty, and creative, and is constantly helping me with something, he also has an ebay account and when I want something from there he gets it for me. He is also my DH's assistant when brewing beer.