When they're not busy switching actresses, Lauren Anne "Laurie" Forman is Eric's sister on That 70's Show.  Laurie is definitely a manipulative *itch and a bit of a slut.  We love her just the same.

Laurie Forman Quotes

(Laurie comes to the basement to do laundry, wearing only a long t-shirt)
Laurie...I want you to stay off my case, it will only take me a minute.
Eric: I don't think Kelso's gonna last that long.
Laurie: Too bad. It's not like I'm completely naked under this. I'm wearning underwear. (she lifts her shirt) See? If we were at the beach you wouldn't even notice me.
Hyde: If we were at the beach, Kelso would be in the water right now.

(Laurie is folding clothes in the basement; she bends over)
Fez: Holy Mother!
Kelso (nervously): Hello, Laurie.
Laurie: Hello, Kelso, Hyde.
Fez: Who's the goddess?
Kelso: The goddess is Eric's sister.
Hyde: She's not a goddess, she's more the earth mother whore type, which works for me.

That 70's Show Quotes

Fez: I'm so excited about Star Whores.
Hyde: Fez man, it's Star Wars.
Fez: Screw that.
Hyde: Hey Forman, man, this thing better be good. If I don't see some space jugs, I'm going to be super pissed.
Eric: Oh, hey, guys, I heard it was okay.
Kelso: Well, there is no way it's better than the Planet of the Apes. I mean, those apes were really good actors.

Eric: If my dad catches me copping beers he'll kill me.
Hyde: I'm willing to take that risk.