For new customers and in-store only, Blockbuster offers a Blockbuster Blue Ticket 30-Day Trial for free via this printable coupon. That's among the best trial offers we've seen from Blockbuster. (We saw a similar online deal in July; this is only valid for in-store rentals.) This applies to both DVD and Blu-ray movies and video games.
Note that this plan will continue at up to $14.99 per month after your trial expires; you must cancel it before the trial is over or you'll be billed for a month's membership.