The four logo I like:
1. The Esperanto-inspired logo, because it relates to something. Other just "look cool" (or not) without any explanation behind it. I don't like the logo itself though, Just the idea to give some meaning to the logo (here, Esperanto is a good idea)
2. "The illusion of a M", for its creativeness. But I looks bulky, heavy, not something I'd like to see in a currency (except if you are talking of the currency of ancient Sparta, which was deliberately difficult to handle)
3. This one is esthatically the one I like the most, but it looks like a superhero logo. Not that kind of feeling I want to convey on a curency
4. Finally, the more classic is the one I am considering the most, at the moment. Granted, it could be refined (you can get a nicer font, a sans-serif would be more adapted
So, to sum it up;
- Logo with a meaning
- Not "in-your-face" logo. This is a currency, not a videogame
- Try to make it creative, like the "illusion of a M"
On top of this: this is only about the logo. You can propose a slogan, but it won't be part of the choice and if the logo is adopted, the slogan could not be - and the other way around,n a slogan could be adopted without the logo to accepted).