I would say that it boils down to preference, but ultimately, Law Review is undoubtedly the best choice. However, if you are absolutely positive that you do not want to work in Big Law (and trust me, not many people are sure what the hell they want while they're in law school), then maybe a specialty journal would be the ideal choice.
I only chose to do Law Review because I am not sure whether I want to do Big Law, but I'm leaning towards not doing it. But if I should change my mind later on down the road, I would be kicking myself for giving up the opportunity to be on Law Review. Yes, one should never do something soley for the prestige factor, but if you're doing it to make yourself more marketable in the job market, then it's nothing but a good thing. Just my two cents.