JarlFrank
I like Thief THIS much
Lastly there's Call to Arms, and it's major mod, Ostfront. Emphasizing on the FPS aspect. It's important to mention, Digitalmindsoft, now self-publishing, as I stated elsewhere, are pretty scummy, "bethesdising" that game with new editions over the last years. The game itself looks good, I haven't played those yet however.
Alienman told me it's good.
If you already own men of war assault squad 2, the Axis Stalingrad campaign in Sir Hinkel’s mod (available on the steam workshop) is a lot of fun.
Got any other single player mod recommendations?