tigerman
smeagol the vile:
The subjects are always the same... why not pick something different? Make a Winter War GB, or a Japan vs China in 38 GB, ANZACs in the pacific, something thats different and cant exactly be bought and done oob?
You're always welcome to start your own. 
They are pretty eclectic and somewhat limited in subjects. The Japanese and Chinese GB would be very limited since neither had much in the way of armor.
I've seen a few good idea never get off the ground, due to lack of advertising, participation, and so on. Subject matter is obviously important.
Blitz in the West - 7
Battle of the Bulge - 6
Honestly, everyone has a different stash and different things that stoke their fancy from build to build, and I think the keys to a great GB with tons of participation probably come down to 1) keeping it general enough that a lot of people and subjects can enter and 2) having some common thread between the subjects.
I honestly think that was one of the problems with my Weathering GB and why it kind of petered out (aside me from being terrible at running it!) - very little of a common thread between different builds going on there, so you'd often have people WIP-ing past one another.
Something like "ANZACs in the Pacific" would obviously have that common thread, but would suffer from the general problem.
The best GB's I've been a part of have had a combination of generality and a common thread. The Natural Metal Finish GB is a great example...very general, but also, most things there tend to be aircraft, and the technique for NMFing one plane is broadly applicable across all other planes.
Conversely, kermit's Ostfront GB is general in the sense that it encompasses a staggering variety - I mean, anything used on the Eastern Front in WW2? I've already built an La-5, Yak-3 and Panzer IV for it. But the common thread is that time period and geography.
Deafpanzer's Pz.III GB kind of combines both. Due to the staggering variety of variants and ausfs, The Panzer III is a very general subject (the only thing comparable I could think of on the allied side would be a VVSS/HVSS build, or on the aircraft side, maybe by engine...I think a P&W R2800 build would be fascinating), but it still has that common thread of...they're all Pz.III platforms, they all have six road wheels per side, and so on.
Also...go Bulge!
On the Bench: 1/32 Trumpeter P-47 | 1/32 Hasegawa Bf 109G | 1/144 Eduard MiG-21MF x2
On Deck: 1/350 HMS Dreadnought
Blog/Completed Builds: doogsmodels.com