Tau Ceti is the prime candidate among known
stars for having
habitable planets, because of its observed
dust disk, and its similarity to our
Sun.
It's a type G8 star with a mass 90% of our Sun's, luminosity a bit less than a half ours, and at a distance of only 12 light years, it's reachable!
Tau Ceti is thus a popular destination in science fiction and RPGs, from Barbarella to Marathon.