Depends what you're looking for. If you want the "Bling Blink" super high-gloss look, I can't tell you what's best. But if you like the dark, clean, new look of a very black tire, but not slick and shiny, then I like 3M Tire Dressing. Of course, use a good tire brush and cleaner first.
I tried both those 2 products, the All extreme Tire Shine and the Meguiars....Both very nice if you want the wet shiny look. I find the Meguiar to last longer