Ah, here it is on Warseer: http://www.warseer.com/forums/showth...of-Old-Legions

Dark Angels: ~100K
Emperor's Children: ~100k
Iron Warriors: ~100k
White Scars: ~100K
Space Wolves: ~30k
Imperial Fists: ~100k
Night Lords: ~100K
Blood Angels: ~100K
Iron Hands: ~100K
World Eaters: ~100K (~70k post Istvaan)
Ultramarines: ~250k (Possibly as little as ~100k post calth)
Death Guard: ~70k
Thousand Sons: ~10k (~1k post Prospero)
Luna Wolves: ~100k
Word Bearers: ~100k (~150k pre-calth)
Salamanders: ~100k
Raven Guard: ~80 (~5k post Istvaan)
Alpha Legion: ~100K
Listed on the first page, and then a few pages or arguments.