A report from the Federal Trade Commission names retailers that are better-- and worse-- at keeping kids away from buying R-rated video games and DVDs.

The FTC sent undercover buyers to the stores to see how often they were able to make a purchase and how often they got carded. Our undercover shopper survey demonstrates some progress, David Vladeck, director of the FTC's Bureau of Consumer Protection, said in a statement. But more needs to be done.

Retailers generally improved over time in preventing minors from buying these forms of entertainment, but some did better than others. According to the FTC's findings, 38 percent of underage shoppers purchased R-rated DVDs, compared to 54 percent in 2009. Video game retailers went from a 20 percent purchase rate in 2009 to 13 percent in 2011. CD retailers went from a 72 percent purchase rate in 2009 to 64 percent in 2011.

The FTC says Best Buy and Wal-Mart are better at keeping kids away from the R-rated media. In terms of R-Rated DVDs, Only 27 percent of underage Wal-Mart customers were successful and 32 percent of Best Buy customers. Target was not as successful, with 61 percent of its underage customers able to purchase an R-rated DVD. The numbers were similar for unrated DVDs (unrated movies must be bought by adults as well).

Target was a bit more vigilant about selling M-rated video games (M stands for mature, the equivalent of a movie's R-rating). Only eight percent of underage Target customers were able to buy M-rated games, whereas 20 percent of Wal-Mart customers and 16 percent of Best Buy customers had success.

The government agency said it recruited 13- to 16-year-olds, unaccompanied by a parent, to buy R-rated movie DVDs, unrated DVDs of movies that were R-rated when first released in theaters, music CDs with the Parental Advisory Label and video games rated M. All of these forms of entertainment have to be bought by someone 17 or older who can prove it with an ID.