Most satisfying - feeling "in the zone" when writing, or cutting and pasting - the whole process of creating the zine really, I just love it! I can forget all my everyday stresses, put on some good music, and just, well, enjoy myself. It's also satisfying to get good feedback on my zines from people who have read them, and to know that another person was able to connect with what I've made.
Most annoying - when I made issue 1 of my zine I didn't think very far ahead (i.e. to the putting-it-together stage) and ended up making it in such a manner that I have to trim the margins of every page and carefully check the page ordering as I didn't number the pages. I've definitely learned from this (and I know it was a stupid mistake that I could easily have avoided with more forethought and less impulsiveness), but issue 1 is a huge pain to put together and for that reason it's going to go out of print quite soon.
The most annoying thing about making zines these days is finding the time to get them done and mailed out. Things were so much easier decades ago when I didn't have responsibility... But when I get a new issue out to the world (a very small one at that), hearing from people around the world about what I write makes it all worth the effort!
Through zinedom I've made friends with hundreds of people around the globe. Many I've kept in contact with for decades! Even on a local level some of my best friends now started as fellow zinesters years ago. I never imagined, 27 years ago, I'd still be making zines today, but here I am. I only hope I take my last breath standing in line at the post office. (If you're next in line, please mail my zines for me.)
I think the best thing is either writing the content and getting everything off my mind, or getting to mail out all my zines, trade with other zinesters, and read people's love letters. :)
The worst thing is getting sticky glue fingers from all the pasting. Another annoying thing is people not mailing out trades, but that's only happened to me twice so far (and the second one showed up eventually, 3 months late).
Some of the most satisfying things about making zines are, for me, learning more and more about how to write & why I write; making friends with some pretty lovely folks & eventually developing close friendships; and just plain giving myself something to do. I like writing, I like cutting & pasting, I like riding my bike to the photocopy shop and the post office. I like writing letters. I also think it's really cool when I'm tabling at a zine fair, and somebody recognizes me without having met before.
Some of the more annoying things about making zines are paying for photocopies, breaking staples when I've got too many pages, feeling zinester burn-out now & then, reading uninspired zines, and occasionally having to ward off the creeps.
like tee rex said it is so satisfying to have a pile of just made zines folded and stapled and waiting to be read. even though i print only 3 or 4 copies, it makes me so happy! and also the thought that maybe something i put so much love into is going to be read and appreciated by another person... like i am giving them a part of myself.
the most annoying thing is when my printer is not working... worse yet, when i want to make zines and write letters and mail things to people but i have to go to school instead!
For me, it's all about the layout. I love putting everything together and working with the technical aspect of it. On the same token, the most annoying thing for me is when the pages don't line up how I want it to or when things get cut up during photocopying and printing. I know that's where the beauty of most zines comes from, but I just want everything that I make to be precise!