If I could interject, this is turning into a casting thread. There's already a thread for that.
Good point. Time for some Loisisms to get us in the mood for talking about how Lois is:
Smallville
Perry: All right, you lovebirds. Tell us what it's like working together and dating.
Clark: It's never been better.
Lois: It's kind of like being on a chain gang with your ball and chain.
Stern: Let me guess. You two have a lovers' spat?
Lois: Clark and I don't spat. There was no spatting.
Zod: I'm General Zod. And all of this is mine to give if you give me the names of whoever snuck you into the restricted zone.
Lois: My Dad's a general, too. And he still couldn't get me to spill how I got an M1 Abrams tank to take me to the prom. So I'm definitely not telling you anything.
Clark: What are you doing here? (reads her thoughts)
Lois: Standing in the shadow of six and a half foot of handsome. No, Lois, he doesn't get off that easy. Kick his ass!
Animated Series
[Lois, kicking herself for asking Superman on a date, talks to herself]
Lois Lane: I understand, Lois. Really, you do? Yep, you're a complete moron. Why thank you, Superman, I think I'm a total loser, too. Jeez.
Lois Lane: I'll get some iodine for that scrape. Burning, STINGING iodine.
Lois Lane: Hey, Clark, keep Bruce company for a minute while I see the Chief, okay?
Clark Kent: Uh, Lois...
Lois Lane: Shh, don't be intimidated. Regale him with stories of
[posh voice]
Lois Lane: the nightlife in Smallville.
Lois Lane: Come on!
Jimmy Olsen: Uh... I'll wait here.
Lois Lane: Oh, for God sake! Don't be such a girl!
Um, how can I put this: I was just thinking... it might be nice to see each other when I wasn't falling out a window or something. Not that I'm not grateful for all the times you've helped me, you understand.
I just hate seeing people miss opportunities. Life's too short.
You wanna keep up with me, you gotta be quick.
You sound too good to be true. What's your secret?
Comics
So... they don't have Irony in the future?
A lot of people talk about the end of the world... but no one really believes it will happen. Surprise.
It's been seventeen months, two weeks, four days and an odd number of hours since you scooped me.
Don't be cute, Kent. You're hard enough to resist without those puppy-dog looks.
Yeah well, don't get all excited, Clarkie-Boy. Denial builds character, and I'm gonna be denying you for a loooonng time.
You can't be everywhere. Nor can you right all the Earth's wrongs... A life... a love... They help you remember what it is you're fighting for...
As much as I'm married to Superman, my heart belongs to Clark.
The fact is, people will always treat Superman differently. You need a secret identity. It's what protects you from people... and it's what connects you to people. Under that costume you're Clark Kent -- you'll always be Clark Kent. You can't live without him... and neither can I!
You'd better take that super-mouth of yours and kiss me with it, Smallville, before I forget why I missed you.
I'm a reporter, not a warrior princess.
If I could have just chosen my parents like dishes on a chinese menu, don't you think I would have picked someone a little less neurotic? Nobody gets to choose their parents, Smallville. We all fall from the stars... into the arms of strangers.
Other
Lex Luthor: But we're not really strangers, are we? This is kind of a little reunion, isn't it? Heck, I'm a fan. I love your writing... and your dress.
Lois Lane: I love your boat. How'd you get it? Swindle some old widow out of her money?
Lex Luthor: [gushes and chuckles mockingly] That's funny. Hey, didn't you win the Pulitzer Prize for my favorite article of all time, 'Why the World DOESN'T Need Superman'?
Lois Lane: Didn't you have a few more years to go on that DOUBLE life sentence?
Lois Lane: Ha! So you admit it!
Molly Flynn: All right, I admit it. But we're still gonna die, so what good does it do?
Lois Lane: Well I feel a little better.
Lois Lane: Do you think I always have to be right?
Clark Kent: Well...not *always*.
Lois Lane: Do you think I'm a good friend?
Clark Kent: Lois, I think you're a great friend.
H.G. Wells: What's the matter, my dear?
Lois: Oh, you've been to the future, Mr. Wells. Is it true what Tempus said about me?
H.G. Wells: Oh, yes. You're as highly-revered as any woman in history.
Lois: Oh, no, I'm meant about being galactically stupid.
H.G. Wells: No, no, no, Miss Lane, not stupid, blind. It is one of the many things that makes your story so timeless. Why children never tire of hearing it at bedtime. Why parents never outgrow it. Generation after generation, we are all blinded by love, Miss Lane. Especially that one great love that changes us forever.
Tempus: Excuse me, but I'm in danger of choking on my own vomit.
Imdb's Quotes Page on the Character:
http://www.imdb.com/character/ch0000198/quotes