10. AIG

2011 advertising spend: $124.7 million

Personal lines direct premium written ($M): 2,087.5

Year-over-year advertising growth: 5.68%

Ratio of advertising to premium: 5.98%

AIG sponsored the Manchester United soccer club up until 2010. Though the company no longer sponsor the team, AIG still managed rank as the number 10 top spender on insurance advertising.

9. Travelers

2011 spend: $166.5 million

Premium written ($M): 7,133.3

Year-over-year advertising growth: 28.86%

Ratio of advertising to premium: 2.33%

Travelers is ranked as the number nine top spender on advertising. PC360 readers ranked the insurer's popular Travelers Dog commercials number three in our Best Insurance Commercials poll.

8. American Family Mutual

2011 spend: $167.3 million

Premium written ($M): 4,669.2

Year-over-year advertising growth: 53.88%

Ratio of advertising to premium: 3.58%

American Family Mutual spent $167.3 million on advertising in 2011, nearly 54 percent more year-over-year, helping the company snag the number eight spot on SNL financial's list.

7. Nationwide

2011 spend: $277.3 million

Premium written ($M): 10,140.7

Year-over-year advertising growth: 1.04%

Ratio of advertising to premium: 2.73%

Nationwide has really invested in its World's Greatest Spokesperson in the World advertising campaign, gaining the number seven ranking on SNL's list. In addition, the company sponsors the Nationwide Arena and the Nationwide Children's Hospital in Columbus as well as sports tournaments like the NASCAR Nationwide Series and the PGA Tour Memorial Tournament.

6. Liberty Mutual

2011 spend: $332.5 million

Premium written ($M): 11,857.9

Year-over-year advertising growth: 16.72%

Ratio of advertising to premium: 2.8%

Liberty Mutual, known for its feel-good television commercials, ranked number six, having spent $332.5 million on advertising in 2011.

5. Farmers

2011 spend: $464.2 million

Premium written ($M): 14,615.7

Year-over-year advertising growth: 29.69%

Ratio of advertising to premium: 3.18%

Farmers ramped up its presence in the insurance ad war on multiple fronts. In addition to the television campaign featuring actor J.K. Simmons, Farmers also purchased the naming rights to Farmers Field in Los Angeles for $700 million, payable over 30 years. Completion of the $1 billion stadium and convention center complex is expected by 2016. Farmers' elevated profile comes at a time when the company is in danger of losing market share.

4. Progressive

2011 spend: $536.1 million

Premium written ($M): 13,453.4

Year-over-year advertising growth: 9.02%

Ratio of advertising to premium: 3.99%

Coming in at number four is Progressive, which is known for its commercials featuring cashier Flo.

3. Allstate

2011 spend: $745.3 million

Premium written ($M): 24,423.8

Year-over-year advertising growth: 11.76%

Ratio of advertising to premium: 3.05%

Allstate is known for its popular “Mayhem” commercials and Sugar Bowl sponsorship, but a purchase in 2011 drove the insurer to becoming third largest spender on the list.

Looking to make inroads into the direct market, Allstate purchased Esurance in 2011 and starting in December, began an aggressive re-branding of Esurance that included a television and radio ad campaign featuring actor John Krasinski of “The Office” and the Grammy Award-winning song “Jam Man” from guitarist Chet Atkins.

(Kevin C. Cox/Getty Images North America)

2. State Farm

2011 spend: $813.5 million

Premium written ($M): 47,576.2

Year-over-year advertising growth: 29.16%

Ratio of advertising to premium: 1.71%

The second-largest spender on advertising is State Farm. The company runs a number of television ads and sponsors many sports tournaments, including the LPGA State Farm Classic golf tournament. Some of State Farm's most popular television ads include its State of Unrest and State of Regret commercials.

(AP Photo/Seth Perlman)

1. GEICO

2011 spend: $993.8 million

Premium written ($M): 15,264.4

Year-over-year advertising growth: 10.09%

Ratio of advertising to premium: 6.51%

GEICO spent 22 percent more on advertising than the second-largest spender State Farm—even though State Farm's ad spending grew at nearly three times the rate GEICO's did.

SNL found that GEICO's ad budget represented 6.5 percent of the premiums it wrote in 2011. Among the rest of the five largest auto insurers in the country, none spent more than 4.9 percent of premiums on ads.

Over the last 20 years, GEICO's share of the market has roughly quadrupled, for which the advertising program usually gets much of the credit. Among U.S. auto insurers, GEICO has a market share of about 8.5 percent, third behind Allstate's 10.2 percent and State Farm's 18.7 percent, according to the Insurance Information Institute.