Carlo Salzani presents a brilliant overview of the current philosophical debate on animal rights by focusing on three authors of recent books. For what it's worth, I lean towards the viewpoints of Milligan and Garner, and not Francione's.
The heterogeneous galaxies of studies revolving around the issue of animal ethics agree on one point: nonhuman animals endure unacceptable levels of suffering due to human exploitation, and this suffering ought to be eliminated. For the rest, philosophers and activists working in this field agree to disagree: they disagree on the moral status of nonhuman animals, on the major goals of pro-animal activism, on the actions to be taken to ameliorate animals’ conditions, on the strategies to adopt, and on the results achieved by the various movements to date. The diversity of theoretical positions and practical approaches, and the growing number of works addressing the problem, have generated an intense internal debate. Two books published in 2010, Gary Francione and Robert Garner’s The Animal Rights Debate and Tony Milligan’s Beyond Animal Rights, help giving a sense of what is presently going on in philosophical circles and mapping the theoretical territory of the animal ethics discourse.
The two books certainly do not (and do not claim to) cover the entire territory, nor attempt to summarize the entire debate; rather, the three authors offer three distinct — and discordant — positions which, though all advocating a revolution in the human treatment of animals, are as distant as the stars in a constellation. Francione and Garner argue that the debate between abolition and regulation of the human use of animal is at the center of modern animal advocacy, and propose two solid and consistent set of arguments: Francione is in favor of the abolition of the human use of animals, while Garner defends a protectionist approach, according to which at least some uses of animals may be justifiable. Milligan, on the other hand, does not propose a thesis or a consistent “package,” but rather attempts a different approach which explores different issues in different ways without relying on fixed and one-dimensional baselines.