They are all pretty good , I have a remark regarding few with the color choices clashing and not fitting the theme such as

.
Maybe it's my own flavor that is flawed but I some how don't think the green leaves (I presume) fit everything,they just pop out and immediately take the focus of the eye which with a render that you have chosen is maybe not the greatest idea.
Try adding few gradient maps,color balance and everything should look great.
Generally you would like to go with some of these gradient maps
Black > White Gradient Map
Red / Black Gradient Map
And experience with others.
That was my constructive critics so hopefully I did not offend you (Your other signatures look amazing).