"Clash of Wings" series from the Discovery Channel. The WWII footage in them is awesome. I watch *a lot* of WWII historical stuff and have seen the clips used in most series many times over, but this series has lots of excellent footage that I had never seen before. Also, this series is almost entirely historical footage.
"Lost Evidence" series from the History Channel. These are excellent, with historical footage and also very high-quality re-enactment (more toward the level of Band of Brothers).
"Battle 360" and "Dogfights" series from the History Channel. Good, although the computer graphics in them is sometimes not top notch.
"WWII in HD" series from the History Channel. Some good historical footage.