55 Cancri

Also known as Rho (1) Cancri.  Almost 41 light years from Earth, this G8V star has at least five planets.  One appears to be in the life zone -- it looks to be a Jovian, but it could have a habitable moon!  55 Cancri also looks to be unusually metal-rich, twice as much so as Sol (well, those planets had to come from somewhere!).

ETA: Bryden et al give an age range of 3.6 to 6.5 billion years; Mamajek and Hildebrand say 7.4 to 8.7.