Second one

ISABEL: I don't know. The whole thing just felt really, um... Dangerous. But I was thrilled by it, by this man, this familiar man. It was pretty erotic. I mean... Don't tell anyone... But when I woke up in the Crashdown, I was so disappointed, I literally had to take a cold shower.
KYLE: That's quite a visual.
ISABEL: Shut up.

-or-

ISABEL: What is this?
MICHAEL: Uh, school project.
ISABEL: Huh. Whose blood is this? Is this Jesse's blood? Are you testing his blood now?
MICHAEL: And he passed! Because I knew he would pass. I told Max-
ISABEL: Max is in on this?
MARIA: Oh, thank god you're here! Oh...Ok... Um, here's the situation. Uh, there's a slight kink in the plans. Your... Your dress is in Florida.
ISABEL: What? What?! Oh, God.

It's so hard to choose. Second.

Max: Liz, please don't shut me out. What are we going to do?
Liz: I have to figure it out. By myself.

or

Liz: Um, did you know there is a full college scholarship offered to potential podiatry practitioners?
Max: Really?
Liz: Have to keep my business south of the equator though.
Max: Couldn't you come a little farther north?

Second one. Kyle always has the greatest lines.

(while making out)
MAX: What a great...mind...you have...
LIZ: Ohh... I don't think that's my mind... but keep looking, I'm sure you'll find it.

-OR-

(while making out again)
LIZ: Tough job...
MAX: Yeah...somebody's gotta do it...

Another tough choice, but the first one.

ISABEL: Something's wrong with Michael. He's acting weird.
MAX: Weirder than usual?

-OR-

MARIA: It's grief relief. It's this herbal remedy that shocks the body back into reality when the mind has gone into overload. Veterinarians use it to calm wild animals.

Second.

MAX: Liz! Liz, what are you doing? We agreed none of us would go anywhere alone.
LIZ: Fine.
MAX: Wait.
LIZ: Max, look. There's just...there's nothing left to say.
MAX: Except the truth.
LIZ: We have already been through this!
MAX: So far, all I know is what I saw, and what I saw can't be true, because it means everything I felt in my heart for the last year is a lie! Now, you owe me an explanation, and I want it right now!
LIZ: Please quit shouting, Max. You're scaring me.
MAX: That's a lie, too! You're not scared. You're hiding something.
LIZ: I'm not.
MAX: What the hell is going on with you, Liz? We never lied to each other, never kept a secret from each other.
LIZ: You know, you have got me up on this pedestal, Max, and...I'm not this perfect person. I made a mistake. Look, Kyle and I made love. The end. I'm sorry.

or

LIZ: I keep looking for some sort of change.
MAX: You mean like...
LIZ: Yeah. Something like that. It's nice to see you smile again.
MAX: I want to thank you for saving my life.
LIZ: I guess that makes us even.
MAX: And...I'd like to...start again...our friendship, that is. I mean...I miss it.
LIZ: Yeah. Um...I miss it, too.
MAX: There's just one thing I have to say. One thing I have to ask...and...I promise I'll never ask it again.
LIZ: Yeah. Go ahead.
MAX: Did you...sleep with Kyle?
MAX: Ok. I'll see you tomorrow.

Second one.

ISABEL: All I know is...Max, you may be the king, but I am not bowing down to you, not in this lifetime.

OR

MAX: We've got to think about the future, the one our mother talked about.
ISABEL: Right, right. The king. I'm sorry. How could I forget?

hands down...it's the first one!

MICHAEL: Do you really think he missed his bus?
LIZ: Yes, i do. Haven't you ever missed a bus before?
MICHAEL: No, 'cause I don't take the bus, and I don't write songs. And I don't cook with freaking half and half.

OR

Maria: After you suggested it'd be better off if I was dead, and Jesse, and everybody else who knows about your little "secret"..!
Michael: It was a suggestion...Why am I always apologizing to you guys about who I am?

Definitely the first one

LONNIE: No three ways tonight, Opie. Maybe later.

-OR-

RATH: Do you want me to kill him for you?
MICHAEL: I'll get back to you on that.

Second.

Kyle: (speaking quickly.) Jesse, Jesse, thank God. Listen to me, look, this is very important. There's an alien on the loose.

Jesse: Yeah, we know. It's Tess.

Kyle: Tess is back?

Jesse: Yeah, she's here. She brought Max's son.

Kyle: She has the baby? Are you kidding me? Ahhhh, my brain is exploding over this... Look, look. Those Air Force guys followed her scent to my place, they'll be there any second.

or

Tess: Michael, do you have any milk?
Michael: No, just Snapple.
Kyle: Can't you breastfeed?

First one. Wow, Jenny you watched FAAAB? I wished I had tapes so I could remind the scene where Liz blasted Tess over and over again.

Maria: Max, little advice. The girl goes off to some aunt in Florida for the entire summer and barely says good-bye to you. In layman's terms, she blew you off big time. I mean, and look at you. Look, you're like a groveling dog. (in a whiny voice) Have you heard from Liz today? Did Liz call? (end whiny voice) No. That's no good. Look, you've gotta play it cool, all right? Let her come to you.

or

Maria: 'When humans need rides they take jettas, and when aliens need rides, they take spaceships. Oh, find one.