My favorite part of making my comic page is when I'm filling in the dialogue, because it means I'm almost done. Least favorite part of making pages is pretty much the entire creation process of laying out the page, filling in the line art etc.
Favorite part: Coming up with ideas and story planning. I love doing character sketches and setting up their personality and backstory. I also like thinking up a story, then thinking "well how can I do this better" and working at it until I am satisfied.
Least favorite part: Line art. The technique I use for my main series is very time consuming. It has to do with the size of the brush and my hand not being the most steady. I have learned that increasing the brush size allows me to work faster, however when I tried this for the series, I hated the way it looked. I tend to use thicker lines on side works.
I really do love the entire creation process of comic making, but the part I don't love is I get so exhausted, that I'm often just too tired to promote it the way I should. It's like...I already spent so many hours on this thing can't I just post and run? but nah...damn promotion.
Favorite part about making comics is creating characters from my imagination. Least favorite part is the amount of time it takes for me to do line art (like what I'm doing right now. Haven't even gotten past 1 panel for the line art). 
Ikr. I'm pretty sure I've found some error that I missed in every single part I've uploaded so far without fail
My favorite part is Writing the plot itself. Especially when I'm choreographing a fight scene. I really love the entire process, drawing it, then coloring it. By sheer process of the elimination the only thing I think like the least is typesetting. Simply because by that point, I've finished all the really creative stuff.
I only write novel cause I don't know how to make a comic. Anyway, my most favorite part in writing is the beginning. It's very exciting and the idea is fresh. Inspiration keeps coming and it's very fun to read comments from my readera. And then my least favorite is the ending. Cause I'm not very good at it and I always have trouble how to end my book. 
I also hate editing cause I'm very bad in grammar, given that English is my third language and I'm too poor to pay someone edit my book.
Best part? The writing its self.
Worst part? Editing. It's a skill I'm still learning and sometimes I feel like I'm always going to struggle with it. No matter how hard I try there's always something I did wrong 
I love creating new stories for each chapter of my comic. I also love thumbnailing.
My least favorite part is repeating the shading. It's repetitive.
for me the least favorite is inking, cause i have to draw the panel again
and my favorite is coloring ^^
My favorite part is being able to bring life to my characters that already mean so much to me. Being able to share why I love them and share my story with other people. I do just enjoy drawing for what it is too.
I'd say that I hate remembering details the most. Just little things like earrings on a character or the shade of specific item. Always have to try to catch it in editing.
The deadlines can be a little overwhelming on top of work but I can't say I hate it? I like being busy and I know without a self imposed deadline I wouldn't get anywhere and just feel lazy.
My favorite part of my comic is anytime I get to draw a monster or something obscure and weird. And just go nuts with it.
My least favorite part is the line art. Definitely the line art, I'm one of those scratchy drawers so getting it nice and clean is a real pain.
Publishing it and then realized that you forgot to erase that one pixel that you forgot to get rid of before
My favorite part is that I get to express myself because sometimes I feel like nobody is making anything I really want, so at least I get to make something to appease that desire.
My least favorite part is, ironically, the very thing I love about it, making something for myself... but am I alienating other people because of it? I create my comic because it is something I want but because I am making it public, I definitely want people to check it out. Though I do have a few readers, I sometimes wonder if the reason why I'm not getting readers is because I'm not being considerate enough of the wants and needs of others.
I love actually creating my story and watching it unfold in unexpected ways. A lot of the time ideas that come up while making pages aren't what I had planned for, and actually BETTER than what I planned!
The part I hate most is actually making my pages presentable. I'm impatient, and just want to get to the good parts, and share them with others! My art can wind up a little messy because of this, and I'm trying to work on that <_<;
Having so many ideas, but not enough time to get them developed or even on paper in some cases. Worst thing is being in the middle of so many projects and then getting an idea for a new one.
Ditto here. I have so many ideas for comics, games, stories, etc. The only remedy I have is to write everything down and take as much notes as possible. It may not be in the beginning stages of production, but at least it exists in some shape and form. I so far am only writing down simple, one sentence notes, but next year, I plan on taking one hour of my day to just plan out these ideas, flesh them out with notes, concept art, and anything else. This beats just having it on your head and not going anywhere.
Ideas are like pets, they'll eventually start begging to go outside.