The Rogue Shadow: from the first 'The Force Unleashed' game.
This build took me almost a year of on-off building and it was certainly the most challenging thing I've ever made with Lego! The hardest things being how to keep its asymmetric shape strong enough to pick up and carry around (it weighs a ton!) + getting the odd 'wing panels' on each side to stay up without sagging whilst being able to rotate 90 degrees.
I used the only floorplan that I could find online as a guide (not sure if it's an official floorplan) and I made sure that it incorporated all of the rooms and features detailed in the wiki page, including bunks for 8 passengers, medical bay, training room and more.
Outside the engine room, you can see a huge stygium crystal which looks decorative, but it actually powers the ship's cloaking device - in the training room I put a few different assassin droids and a large selection of melee weapons for Starkiller to keep his fighting skills up and next to that there's a small 'Focus Chamber' for him to channel his dark energies! .... anyway I hope you like my build - and thanks for looking!