The first three look overly orange/saturated (and a bit dark, in the first.) Also, the rail in the first is slightly distracting.
#6 is probably my favorite of the bunch. I like how the crack in the pavement leads my eye to the skateboarder on the platform. I might have moved in a little closer, so my foreground began where that bold, horizontal break in the pavement is. The sky in this photo is also the most pleasant of them all. Nice job.