One of the reasons for going to GamesDay are the huge display games, my personal favourites are the ones form Forge World.
This one representing part of the Siege of Vraks had titans, super heavy tanks, and lots of trenches and guns.
Here is a Death Korps of Krieg Heavy Mortar, field artillery is often used by Imperial Guard commanders to pound enemy positions.
To see more pictures from GamesDay 2008 have a look at my GamesDay 2008 Gallery.