There is not really one best stylus for writing because it comes down to a pairing between the stylus and the app, as well as personal preference. Do you have an app that you would like to use?
The best combination I have found so far is the Adonit Jot Touch and Goodnotes. The Touch is extremely accurate with no offset between the tip and what you are writing, and Goodnotes has excellent palm rejection meaning you can write full-screen as you would on a piece of paper without messing about with zoom boxes or manual palm rests.
I have the Adonit Jot Script that I just received today, and while it is great to not have the disc on the tip, the offset is huge. I find the writing feel (on an iPad Air) to be similar between the two. I'll probably hold on to the Script for a while yet to see if it can be improved further, but we'll see.