I've done quite a few ficathons, including remixes (gen_remix, remixthedrabble), lyric wheels, and the Finish-a-thon. I even participated in Yuletide once! I've never done a Big Bang, mostly because the word counts are too long for me to guarantee that I'll finish.
My favorite ficathon/fest was definitely the 3 or 4 stories I wrote for numb3rswriteoff. Prompt-based, team competition, which gave me the opportunity to write some really fun stuff. It was run in a playful manner, as well, which is great; but the mods kept a firm hand on it at the same time. Altogether delightful experience!
23 – When you post, where do you post to? Just your journal? Just an archive? Your own personal site?
24 – Betaing – How many betas do you like to use to make sure there aren't any major flaws in your fic? Do you have a Beta horror story or dream story?
25 – Music – Do you listen to music while you write? Do you make playlists to get into a certain "mood" to write your fic? Do you need noise in general? Or do you need it completely quiet?
26 – What is the oddest (or funnest) thing you've had to research for a fic?
27 – Where is your favorite place to write, and do you write by hand or on the computer?
28 – Have you ever collaborated with anyone else, whether writing together, or having an artist work on a piece about your fic?
29 – What is your current project or projects?
30 – Do you have a favorite fic you've written? What makes it your favorite? And don't forget to give us a link!