I used SkypeCallExporter (see the link that already was given and scroll further down for the download). Skype leaves history of all your actions on your computer's hard drive. If you didn't change computer or re-install windows in the mean while, all your history should still be available. I got the list of all the calls (Skype-to-Skype incoming, outgoing and Skype-Out) from the last three years. It's a file you can open in Excel, with a bit of Excel skills you should organize your data to different colums, delete useless information (calls to/from other contacts).
Our Skype Call List is quite impressive (9 pages in a small font size). I'm not sending my chat logs to CIC, something with privacy. They don't need to know what exactly we talked about, the fact that we were in contact all that time should be enough.
Additionally: Maybe in Outlook (Express) do a search on email received from and sent to your spouse and print a screen shot of the search screen showing how many results showed up? I'm sure you can do something simular in Hotmail, Live Mail of Gmail.