Favourite launcher is a toss up between Google Now and Nova Prime. Normally when I use Nova I have it sent up pretty much like the Google Now launcher. If I had to choose I would select Nova - it has everything that I would possibly need in a launcher. Great customisability, super fast, smooth and easy to play about with.
I don't really have a worse launcher, as there are too many launchers to play about with. I'm sure along the way I will discover a few nasty launchers, the only one I can think of right now would have to be the launcher 8. It looked weird on my Note 4 I thought.
In saying that, my Note 4 rocking the latest version of touchwiz is a match made in heaven for me. Looking forward to lollipop update, if I don't like that then off to Nova we go