iKon El Jefe. v1 is best, due to its adjustability.
The I idiot proof shave of the core is definitely the reason for me to keep it.I will put in a vote for the One Blade Core. For $20 it is hard to go wrong. There is basically no learning curve and it is a good razor to have when you are in a hurry as it is pretty much foolproof. I use mine to clean up after a straight razor shave and to do the back of my neck unless I am going to use my Valet Auto Strop. They both use the same Feather blades!
It is also good for travel.