I have always liked the (Epic 40,000) Imperial Guard Manticore model. It is something about those large missiles which makes this look like an artillery piece which means business.
I was always disappointed as a result with the Forgeworld version which looks less like an artillery piece and more like an anti-aircraft weapon or a much lighter artillery piece.
Thinking about it, I wonder if I could (or should) build a 40K scale version?
Model from Felix’s collection, see more Epic artillery.