Corellian Corvette, alias Blockade Runner, is the first ship seen in the first Star Wars movie... In the game world, it is widely used by rebellion and other factions also.
Another crazy project of mine. Some days I think I have time for everything, and I try to do everything... I was preparing ground combat rules for very small scale Star Wars miniatures, but I never got them finished. I've got a bunch of scratchbuilt or modified small miniatures though, and now that I've found Savage Worlds and it's mass combat rules, I can create battles using miniatures as counters! If you're a Savage Worlds fan, you might want to read my post about starship battles.
Victory-class Star Destroyer is another vessel not seen in movies. It is predecessor of Imperial Star Destroyer, is 900 m long and has seen it's best years during the old republic. Although it's too slow to be too effective in ship-to-ship -combat, it still excels in one area: It is still the largest ship able to enter a planet's atmosphere. Combined with it's heavy weaponry, this attribute makes it excellent ground assault craft.
Remember the opening scene of Babylon 5 (not the pilot, the actual series), where Narn fleet attacks a Centauri space station in Ragesh III I was sold the moment I saw that, as it made an immediate connection to my favourite PC game intro - Master of Orion 2.