Dylan--Rainy Day Woman Deep Purple Speed King the first few seconds of Whole Lotta Love Joni--Big Yellow Taxi Chantilly Lace--any number of versions Brain Damage Oh yea, and no Beatles anthology songs allowed either.
Whitney Houston-I Want To Dance With Somebody Who Loves Me Faith No More-Surprise, You're Dead Bell Biv DeVoe-Poison The end of Janet Jackson's "Alright" on the album, although it's not within the song itself Pink Floyd-Sheep Parliament-Mothership Connection Napolean XIV-They're Coming To Take Me Away, Ha-Haaa! James Brown-It's A New Day (So Let A Man Come In And Do The Popcorn) There's loads of James Brown stuff, since he always used to talk to his band during the sessions. As in: "Maceo, you done be tryin' to go up in here, but she say no, no need to get on top my eh HA HA HA HA, so Maceo? Maceo? I got two muffins from the diner and I want you to butter it two times. Two times. Right... NOW!"
Paul Simon allows himself a rare chuckle on Simon and Garfunkle's "At the Zoo" -- just before going into the second verse.
Billy Joel - "You're Only Human (Second Wind)" At least, I believe I'd read that the laugh was unintentional, after he studdered over the previous line.
She's not actually "the singer" in it, but Grace Slick lets out a wonderful horse laugh at the very end of "A Small Package of Value Will Come to You Shortly" from Jefferson Airplane's After Bathing at Baxter's album.
Elvis laughs during "Baby Let's Play House" Lou Reed lets out a demented laugh in the VU's "Heroin", just after the line "it's my wife and it's my life..."