Out of the seven names you have mentioned I have visited the blog of three people and I have also interacted with only three of them. So I am basically judging this only out of three.
Amongst these these three, I have followed @future24 for a few months in the past and enjoyed his posts for a while. On the other hand I am also keeping an eye @mindtrap as a person whom I might follow in the future.
I had to think for a while, but I would like to choose @future24 (Jonas) as my favorite in this list. He is basically from Germany and he also travels a lot. So even when he is at home sharing pictures from around his city, he would make a post from his past travels. This sudden change of pace brought about a nice contrast in his posts and kept things interesting.
What I enjoyed the most about him was that he kept his posts casual. For a serious guy like me he provided the much needed causal relief from the hectic Steem life.
PS: During the last few months I had to unfollow a lot of people so as to try to keep my following list manageable. Unfortunately I had to unfollow Jonas at that time. That doesn't mean that I wouldn't like to add him again to my list :-)