What I really like about #104 is the clever Escher-like logo. The background pattern may be slightly better in #129, but what would clinch it for me is a 3D aspect rather than a show-through pattern.
Here's a concept based of an earlier design, I forget which number. It's the lettermark (a very cool one at that) wrapped around a sphere, oh wait I mean a singularity :)
Hope you like them. You can tell I want to win this contest.