I've gone through several of the Gundam series in one sitting. the longest was when I did a Rurouni Kenshin marathon

Mine was Sakura and Fuushigi Yuugi (though I dont like it much)

i watch school rumble 1 & 2 in two days, that is my best record!

i've watched 30 hours without breaks!
no lies!
it happened when i watched bleach from episode 1 until 70++
i'm eating and drinking in front of computer...
paused a few momont to pee...
and the result was 30 ++ hours of non-stop watching anime!
after that i feel so exahusted that i don't watch anime for 3 days...

2 days without a break... when finishing Ueki no Housoku and Full Metal Alchemist

saber marionette 6 hours a day for two days in a weekend, and death note, the whole thing in a weekend too xD, just in time to wait a copule of weeks for the final espisode

idk how many hour but it was ... tooo much .. lol.. like 4 disk (4Gb)(26 episode) in 3 days somehing near that

my longest is easily 5 hours watching gundam seed and alot of destiny.

I watched the whole Fruits Basket in one sitting... then again the next day. hahaha

Erm...actually i can watch for long hours without breaks but what i feared is that my dvd player cant keep up with me and "BAM" it broke T.T I busted one of my dvd player before becoz i watch from morning till night @.@ So now the furtherest i can watch without breaking my dvd player is about 24 episodes in one watch.

haha naruto tons of nonsense fillers, that's why i gave up watching this series, just reading its manga, skipping the filler part.

i think it was just two days ago.i just use 1 day to finish romeo to juliet 18 to 24 and straight away was kaze no stigma 1 to 24.^^

hmm i think the longest i've watched an anime in one sitting is maybe 9 hours. i was watching suzuka and now i feel that was a waste of time.

About 42 hours with 3 hours of sleep. Watched Gundam Seed and Gundam Seed Destiny in one go

Friday night at some point to 11pm on Sunday. In that stretch we watched all of Evangelion, Hellsing, Pretty Girl Magical Sammy, FL CL, some of Najica and various other things. End of Eva is probably not the best thing to watch after 48hrs without sleep.If you attempt the same make sure of the following: 1) you have a way to get a draft through the room [over a dozen people in an enclosed space gets smelly], 2) you lay in a toaster and a lot of potato waffles [you will need to eat, and more complicated food prep leads to reduced anime watching time.

You win DarksideXD!
My record is 4 hours.

AXN anime marathon, which was long long time ago.
forgot how long though...

But i deproved now. =[[[[
Abt 30eps only (each 20mins, since i dled it i skip all commericals =p)

I can't remember exactly how long it was, but I watched four different 13 episode animes and the first 26 episodes of Gundam Seed Destiny in one sitting. Never again will I watch anime in such a manner

From memory it was Ah! My Goddess S1 (11hrs~), OVA (2 & 1/2 hrs~) then the movie, though we fell asleep watching that as it was 6am by that time =p

Thats from recent memory though. I do have periods where i get right into an anime mood

One day though i plan to do a sailor moon(first 2 seasons)/cardcaptor sakura marathon, which is a total of 30 dvds lol!

I've done a few marathons with friends, but we always break for videogames...so the longest continuous session I've had is probably only about 6 hours.