I think it was TenCents who said that his/her favorite writer is Jake Farrow, which inspired me to create this blog. :)
So, yeah, do you have a favorite writer for iCarly?
Ironically, Dan Schnieder doesn't always write the best episodes. Episodes like iWant A World Record, iGot a Hot Room and iStart a Fanwar are only okay, in my opinion. He does write good ones like iQuit iCarly, iBelieve in Bigfoot, iChristmas, iLike Jake and of course, iKiss! ;)
Jake Farrow seems to write very "Sam-centric" episodes that deal with her character development, like iMake Sam Girlier, iReunite With Missy, and iSam's Mom. He has written very good episodes, overall, like iSpace Out, iTake On Dingo, and the already mentioned iReunite With Missy.
Andrew Hill Newman appears to be a Creddie shipper, because all the episodes he writes seem to have major Creddie moments in it: iRocked The Vote, iGo To Japan (co-wrote), iSpeed Date, etc. Nevertheless, he writes pretty good episodes.
Arthur Gradstein wrote a couple Season 1 episodes, iMove Out, and the highly popular iGet Pranky.
Peter Tibbals and Eric Goldburg are my personal favorites; they have written some very good episodes, like iMust Have Locker 239, iTwins and iSaved Your Life.
If I recall correctly, George Doty IV only wrote iGive Away a Car and iGo Nuclear, which were both decent episodes.
Steve Holland wrote iWill Date Freddie, iWant More Viewers (co-wrote), iNevel, iThink They Kissed, and iBeat The Heat. Again, decent episodes.
Matt Fleckenstein wrote the mediocre iSell Penny Tees, but he also wrote awesome episodes like iFix a Popstar and iHave My Principals.
EDIT: While doing research for this blog, I realized that TenCents did a blog on the very same topic! I didn't mean to steal his/her idea; I just drew inspiration from one of his/her comments.