The Initiative : season 4.7 : Riley is starting to really notice Buffy, and Graham and Forrest are introduced as side characters. Forrest enjoys ogling ladies as they walk by and encourages Riley to get to know Buffy. This is also the first time Riley 'pulls rank' on Forrest, refusing to accept Forrest's suggestion to use Buffy as bait for an escaped demonic prisoner.
Pangs : season 4.8 : The thanksgiving episode, which, fine I'm rambling, is probably a good lesson for white viewers who let people of colour walk all over them and need to re-affirm their own right to live in spite of the empowering or disempowering decisions made by their own ancestors. It is a really shitty episode for people of colour. I view it as just an overdone concept - white/innocent guy meets someone who's been done wrong, white/innocent tries to reason with them, can't, and absolutely-positively-no-moral-doubt has to kill them to get away because the other/person of colour is obsessed/insane/harmful/etc... In my opinion this ep was a waste of space. Who do they think they're kidding anyway? As if we can't see through the trappings down to the bones and end result of that repetitive plot? Themselves, I guess.
Anyhow, Forrest doesn't have much time in this episode, but we do begin to see playful verbal sparring between the two (Forrest and Riley), a forshadowing of what's to come. He tells Riley not to worry about Spike (hostile 17), who has escaped from the Initiative, because the implant preventing the vampire from hurting any living thing is fully functional. Riley responds that he wants to do things Professor Walsh's way and recapture Spike. Forrest gives him the 'momma's boy' cough, and Riley mentions that Forrest might have to stay behind in quarantine instead of going home to his family for Thanksgiving.
Hush : season 4.10 : Forrest has two scenes in this episode, one in which he calls Riley "brother" and tells him that he should really hook up with Buffy. Forrest also has a tense elevator scene with Riley, in which they try to avoid being gassed to death. Yikes!
Doomed : season 4.11 : Riley finds out Buffy is the slayer, and he asks Forrest if he's ever heard of such a thing. This is where Forrest tells Riley the Slayer is a story demons tell their children to make them behave, and he also mentions that demons are 'just animals'.
The "I" in Team : season 4.13 : This is the episode in which Buffy joins the Initiative, asks too many questions and almost meets her doom at the hands of Professor Walsh. In this episode, Forrest becomes upset when Riley chooses Buffy to be his second in command instead of him.
Goodbye, Iowa : 14.4 : Professor Walsh has been murdered by her creation, and everyone is freaked about different things. Forrest tells Riley that if Prof. Walsh tried to kill her, "...maybe Buffy needed killing." In another scene where they discover Prof. Walsh's body skewered, Forrest tells Riley that Buffy must have done it, and calls her a "supernatural freak".
This Year's Girl : season 14.15 : Forrest urges Riley, who is recuperating from being skewered by Adam, to stay in the hospital and heal. He also tries to get him to stay away from Buffy.
Who Are You : season 14.16 : Forrest talks to Buffy (who is merely a bony, crunchy shell in this episode for a creamy Faith filling), and implies that she is killing him with her sexual demands (My So-Called Life fans will get a hoot out of the above sentence).
New Moon Rising : season 14.19 : Oz returns in this episode and wolfs out. Simultaneously, one of the Initiative members is killed, and they suspect he did it. Forrest has a bit part in this episode.
The Yoko Factor : season 14.20 : Spike succeeds in tearing the gang apart, and this is the infamous episode where Buffy says, "I'm starting to understand why there's no prophecy about a chosen one and her friends."
Primeval: season 41.21 : FrankenForrest (who has been killed and 'transformed' by Adam) tells Riley that he will enjoy making him watch while he kills Buffy, and that soon Riley will be one of them again. Then Riley blows him up with an oxygen tank, and he meets his true end.