I almost always build my Trident V2 at .41 ohms on the dot. I do a 26 gauge 7 wrap dual coil, and it's a sleeper, so it's all one piece of wire. Little difficult to do on other attys, but the Trident has slotted connectors, rather than holes to put the wires in, so I just assemble the entire dual coil, and lay it in there. I've also had pretty good success with 30 gauge braided wire at around .4 ohms. The braided wire takes a bit to spool up, but other than that, it's very good. An abyss coil (mesh wrapped over kanthal) might be worth doing too, or mundys magic wire (some combination of twisted kanthal and ribbon wire). I did an abyss once, but didn't like it for some reason. It was a long time ago though.
I have no experience with ribbon wire myself. I have a small amount of it that I would like to try, but haven't gotten the motivation yet