Hyperdrive
Hyperdrive is a fictional propulsion system that allows a starship to complete interstellar journeys through hyperspace. Hyperdrive is a common method of faster-than-light travel in science fiction.
Star Wars
Ships in Star Wars use hyperdrive that allow starships, from massive ISDs to small fighters such as the X-wing, to travel across the galaxy in a few hours or days at most.
Speed
Hyperdrive allows ships to travel the galaxy in a matter of hours or days.
According to the Behind the Magic CD-ROM, the direct travel time from Coruscant to Tatooine is over three weeks while the travel time from Corellia to Tatooine is only four hours, despite both Corellia and Coruscant being in the galactic core.
If one assumes that Corellia is 30,000 light years from Tatooine, then it is possible to arrive at a figure of 65 million times the speed of light. Even the slowest route listed, Coruscant to Tatooine direct, is still over 500,000 c.
If we assume that the Millennium Falcon spent eight hours in hyperspace to get to Alderaan, and that it traveled 30,000 light years to do so, we still arrive at a figure of slightly more than 32 million c.
Stargate
In Stargate, hyperdrive is a common method of moving starships between star systems and even galaxies. Hyperdrive is primarily used for objects too large to pass through a stargate.
Speed
Cronus' mothership could travel at 32,000c.
The Daedalus-class battlecruisers regularly travel between Earth and Atlantis in eighteen days. That gives a speed of 60,875,001c. With a ZPM that speed increases to 273,937,500c.
The BC-303 Prometheus could travel to Atlantis from Earth to Atlantis in three weeks, that's 52,178,570c.
The Tel'tek that SG-1 took to Proclarush Taonas was capable of getting to Halla in 10 days. Assuming Halla is ~4,000,000 Light-years away, that equates to 146,100,000c.
Babylon 5
Large ships in Babylon 5 can carry "jump engines" that will open wormholes into hyperspace, where interstellar journeys can be completed in a matter of hours or days. Smaller ships can use relatively immobile "jump gates" to enter hyperspace, emerging through another jump gate at their destination.