Dean Essig and The Gamers pretty much brought operational-level wargames to their current popularity with his OCS rules. I missed out on all the early parts of it's history, and have yet to get a lot of experience with the system, but it is an ambitious and flexible design, with some very interesting points, and an emphasis on supply consumption. It's supposed to be able to handle WWI, but no titles for that period have emerged yet. What has come out has been nicely diverse, and attracted a strong following.

After Action Reports:

Reluctant Offensive

Links:

Collection Status
Beyond the Rhine	The Blitzkrieg Legend	Burma
Guderian's Blitzkrieg II	Korea	Reluctant Enemies
Sicily II	Smolensk	Tunisia II
Key: Blue=Preordered Mark: Jason: