The closest star to Earth (after the Sun) is well-known: Alpha Centauri, 4.3 light years away. But what about the closest exoplanet to Earth, outside of the Solar System?
Funnily enough, just until recently, the nearest exoplanet Alpha Centauri Bb was believed to be
Source: Nearest exoplanet to Earth may be a ghost world (Aron, 2013). However, according to the article, recent observations have suggested that it may not actually be there. So the answer to this question is not all that clear.
The Paris Observatory has a list of all exoplanets in a sortable database at exoplanet.eu.
According to the Paris Observatory catalogue, if Alpha Centauri Bb does not actually exist, the next closest is the just-larger-than Jupiter sized Epsilon Eradani B (not a hot-Jupiter), at 10.5 light years away. Which according to Nearest Planet Beyond Solar System Might Be Photogenic (Than, 2006):
There is speculation that more planets may exist in that system as with dust rings.