Accessible from the Geoscape, a list of all soldiers you've had in your current game; along with their status (Active, KIA, MIA, Retired); their picture, rank, medals (if any); as well as either a simple mission/kill count, or even better: A detailed list of missions with semi-detailed stats for each mission; example in spoiler.
Related is a similarly laid out list of all previous Xenonaut missions.