Plastic block wunderkind Sven Junga has built some of our favorite interstellar dreadnoughts. Check out his renditions of the Daedalus from Stargate Atlantis, the HAVw A6 Juggernaut from Revenge of the Sith, and more. Here's the Daedalus.
HAVw A6 Juggernaut
HAVw A6 Juggernaut (interior)
R14 Bulldog Class Heavy Fighter