It is Season 4, Episode 10
In the first episode of season 5 "Buffy vs. Dracula"
its a slow process...there was never an episode where willow was just kinda 'I'm gay' but the episode where she comes out to Buffy is season 4 episode 19 "New Moon Rising" the first episode you see Tara, which may be the episode where willow "goes gay" is season 4 episode 10 "Hush" you don't see willow's first gay kiss, however, until season 5 episode 16 "The Body"
"Dead Things" is the 13th episode of season 6 of the television series Buffy the Vampire Slayer.
the first in the fith season "Buffy vs. Dracular"
It's an episode called Seeing Red, episode 19 of season 6.
The episode is called 'Gone' and it's in season 6, episode 11. In the entire Buffy collection it is episode 111...I think. Somewhere around there anyway.
the killer in me season 7 episode 13
Season 3 episode 18, Earshot
Season 7 Episode 3 "Same Time, Same Place"
"The Body" is an episode in the 5th season of Buffy the Vampire Slayer ... one of the best episodes of the show.
On the episode "Dopplegangland" in season 3 of Buffy, Willow has a stunt double.
Season 2, episode 3.