Many people find economics a boring topic, which can lead some to assume economists themselves are boring. Historically though, the profession has produced some pretty passionate writing. Despite the dry sounding title, Keynes' The General Theory of Employment, Interest, and Money is at times an intense polemic against contemporary economic ideas and includes some scathing critiques of Pigou.
With the refocusing of economics as a math based science, most arguments these days are disagreements over assumptions and, while sometimes animated, can seem a little pedantic.
Enter the financial crisis.
Greg Mankiw has been posting a long series of disagreements over stimulus plans in general, but the heat has been turned up by a Paul Krugman post over at the NYT attacking Greg and other skeptics. Greg has given a short reply. Krugman's disagreement with his critics are still somewhat civil, though he can definitely be more animated, such as his debate with O'Reilly on CNBC (video here, transcript here).