• by David Goetzl  @dgoetzl, March 27, 2012

Fifteen brands from Coke to HBO to National Geographic Magazine to Southwest Airlines have outpaced category competitors in overall strength for the eighth year in a row, according to the Harris Poll EquiTrend study.

The research looked at 1,500-plus brands across 127 categories. The 15 “mega brands” have maintained their top spots since the study was launched. 

Among them are some of the largest advertisers in the country, including Subway in the quick-service restaurant segment, Gatorade in sports drinks and Verizon for mobile networks. Southwest is a massive advertiser in televised sports events. 

Oreos, which leads in cookies, has established a significant social media presence, which may have added to its dominance. HBO continues to lead among pay-cable TV networks despite a surge at Showtime.

Others among the eight-year category leaders are Hallmark cards, Holiday Inn and Craftsman among power tools.

The Harris Poll said all are succeeding in “brand momentum,” where “a brand must be seen as leader, be popular among friends and family, have high levels of visibility, be exciting and engaging and be a brand that consumers believe has a bright future.”

In the media sector, current category leaders outside the “mega brands” include CBS in the “TV network” segment and History Channel for “topical interest TV programming.” The Weather Channel led “among “TV news,” outpacing Fox News and CNN. Perhaps also surprising is PBS Kids Sprout leading in “kids TV,” where Disney Channel and Nickelodeon are also players.

In addition to Nat Geo in “general interest magazine,” Real Simple topped the chart in “women’s magazine” and The Economist in “weekly news magazine.”

The research was culled from an online survey of 38,500 U.S. consumers ages 15-plus conducted from Jan. 31 to Feb. 20 that took about 40 minutes to complete.

Respondents were asked to each rate 40 randomly selected brands. The results were weighted to reflect the full U.S.