From Open Secrets: Top Lobbying Firms

 - Click here for the article.

Here are the top 5: 

Akin, Gump et al - $42,800,000

Brownstein, Hyatt et al - $39,540,000

BGR Group - $29,320,000

Squire Patton Boggs - $25,695,000

Holland & Knight - $24,590,000