FDP. Merkel is too leftish for my tastes, I'm obviously not voting for a left-wing party and I also generally don't vote for right-wing populists (though I might have considered the AfD when it was still led by Lucke).
On certain things, it seems like FDP is becoming more center-right than Merkel. Londoner did a really good job building up the party.
I used to like AfD more but I favor FDP because it's more where I am politically. I like that it advocates more for helping the environment and being more welcoming towards immigration (not saying AfD itself is anti-all immigration but some of the members are) while also stating that a more realistic limit on refugees needs to be put in place