Batman, for all the shows various faults and misconceptions it generated, did manage to briefly capture the attention of tv viewers and made a lasting cultural impact that still hasn't fully gone away. While the last decade of Marvel movies have been very successful in terms of box office, they haven't made the same level of impact culturally or in regards to increased sales on the books. The last time I can remember comic stores really benefiting from a movie release was back in 1989 when the first Tim Burton Batman film hit and kicked off another wave of Batmania. 

As for The Walking Dead, it does pretty well for an independent title but it really shines with regards to the tpb sales. It dominates the tpb charts and sells well in that format both in comic stores, internet sites like Amazon and through bookstores. The popularity of the show is certainly a huge factor in people checking it out. However, TWD seems to be an anomaly as that kind of attention/sales symbiosis doesn't seem to carry over to anything else these days.

This probably sums it up best. 

Difficulty finding comics and/or the dissimilarity between them and the hit films may be factors today.  But it's also true that in 1979, DC was hoping for and expecting a big Batman-style sales bump from the Superman movie, and nothing of any consequence materialized.  Looking at the statements of ownership data collected here, the sales of Superman went up moderately in 1979 (from 223,000 to 246,000) while the sales of Action dropped that same amount (from 183,000 to 160,000).  So no net gain in sales on the two flagship Superman titles.  In like manner, Wonder Woman doesn't seem to have benefited from her TV show, with sales of 150,000 in 1975 and 1976, and 151,954 in 1977. 

Is there any instance in comics history aside from Batman in 1966 in which comics have had a significant sales increase attributable to success of a character in other media?

But, as Steve De Young lists above, none of the Marvel big guns (Captain America, Thor, Iron Man, Hulk, or even the roster of the Avengers) were even the same people in the comics during the 10-year period the movies with those characters were making billions of dollars and making millions of new fans.  And, while DC wisely brought back Hal Jordan and Barry Allen in time for their movie/TV show premieres, they do seem to be going out of their way to make sure that they have multiple versions of the same characters confusingly running around at the same time.  (The Superman of the movies does not really match the TV Superman of SMALLVILLE or SUPERGIRL, and they don't match the animation, and none of them match the married father of the comics.  And you can say pretty much the same about Batman, the Flash, Aquaman, etc.)

It could be said that this is the Golden Age of Promotion for these characters we love, as their movies and TV shows have been embraced by society at large.  Yet, with all this free publicity, Marvel and DC Comics have dropped the ball and missed a gigantic opportunity that may not last or ever come again.