First off, you're a great sig maker, Colin, and I think you're one of the best here, but I have to be brutally honest that I think your Amare sig is one of your worst works. (That, and c0n4d's Michael Jordan sig. I believe I've already critiqued him on that one.)
The first words that come to me are: dull, flat and stagnant. I see you're trying to make a relation with the environment (Phoenix) with the player, but the way you depict it is so contradictory. When I think of Phoenix, I think of fire, movement, energy. There's no movement, there's no excitement. Like the rocks, it's just dull and stagnant. Maybe you tried to create movement with the action of the player and the diagonal slopes of the rocks, ending off with "Amare" at the bottom. The way I see it, they're just vertical alignments of elements, confirmed with the awful diagonal background. The color and uniformity of the background is what causes the flatness of the overall composition. The text "Amare" looks dynamic, and could've worked if there was more movement in the composition, but it contradicts with the overall feel. The image of Amare could've worked if more of himself was shown. The way it's shown, his movement is static, for all I know, he could be just standing there with his hands in the air, rather than jumping prior to release.
I think it's nice that you're leaning away from the boring, repetitive custom brushstrokes that virtually 95% of sig makers use, but in this case, it probably would've worked better. The blending of the Suns logo against the rocks is a nice touch. The yellow could be toned down to blend in more with the rocks (without losing the contrast), though.
I hope you liked my critique

if you were killed tomorrow, i WOULDNT GO 2 UR FUNERAL CUZ ID B N JAIL 4 KILLIN THE MOTHA FUCKER THAT KILLED U!
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