While '50/50' may not be Seth Rogen's first dark comedy about coming to grips with cancer (2009's 'Funny People' holds that distinction), it may prove to be his best. Joseph Gordon-Levitt, Bryce Dallas Howard, Anna Kendrick and Anjelica Houston, is reason for optimism.

Inspired by the personal experiences of screenwriter (and 'Da Ali G' show veteran) Will Reiser, '50/50' stars Joseph Gordon-Levitt as Adam, a 27-year-old whose carefree prime gets rather rudely interrupted when doctors discover a malignant tumor. His best friend, Kyle (played by Rogen), helps Adam break the news to his mom (Anjelica Houston) and girlfriend (Bryce Dallas Howard), and come to terms with being sick.

'50/50' doesn't open until September 30, but Moviefone and gofobo are offering FREE sneak previews for audiences in 10 cities. The first 100 people in each city to sign up will receive free tickets for themselves and a guest.

Click through to enter and win free tickets to a sneak preview of '50/50' near you.