Spice & Wolf, Persona, and Rosario to Vampire come next, with others strung out behind. It's hard to gauge how popular Minami-ke O-kawari is, since it is simply continuing the original series' threads (and is on its 96th).
Here is a rough list showing which thread each show is currently on. Each completed thread represents about 1000 posts.
Zoku Zetsubou Sensei 67
True Tears 17
Spice & Wolf 9
Rosario to Vampire 8
Hakaba Kitarou 7
ARIA the Origination 6
Hatenkou Yuugi 3
Major 4 3
Moegaku 5 1
- true tears is getting the attention I think it deserves.
- Yattaman's popularity shows the effect of its long history.
- With all its faults, I enjoy Ayakashi more than 2channel does.
- Hatenkou Yuugi's low popularity is a further demonstration of 2channel's allergy to any anime that can be classed as shoujo.
- Moegaku 5 is more an educational variety show than an anime show, even though it has an anime element.
- A show or two may be missing since I included only the top 100 most recently posted-to threads.
- thanks to tj han and to the geek by any other name for various corrections.