Fifth Invasion has been lots of fun. The War of the Nine Realms was what really got me into BM.
But my personal favourite though was OG/Sint/Thalmarkin's opening campaign against Fronen in 2011. A handful of us spent two or three months carefully planning and negotiating everything. Even though there was a leak to Fronen shortly before the assault began, it went off flawlessly; we overran four regions including a city (Vore) and a townsland (Yipinalke) in the first week or so. The battles themselves weren't all that impressive, but it was beautiful to just see everything we'd worked on fall into place.
