Of course there are many brilliant lines in each episode, but here are my particular favourites (to be updated each day):
Abu Dhabi
Douglas: Again, I fear you flatter my knowledge of cat pathology.
Boston
Martin: Where's Carolyn?or:
Douglas: Sharpening her teeth.
Arthur: Brushing.
Douglas: Brushing her teeth. Yes, sorry.
Arthur: I didn’t know you for very long, Mr. Leeman, but I'll always remember you as ... as a shouty man. You loved to shout; shout and smoke – those were your twin passions. And so, in a way, I suppose you died doing what you loved: shouting and smoking, and covered in foam. I don't know if you liked that. You probably didn’t.
Cremona
Arthur: The thing is, is it unprofessional to tell a passenger that you once made a collage of her face out of pasta shapes?
Douglas: Hmm, I really don’t know.
Arthur: You see, part of me thinks ...
Douglas: Oh, I’m sorry. Did I say "know"? I meant "care". I don’t really care.
Douz
Martin: Right. Well, I've made my point anyway.
Jutteau: You've made it. I 'ave disagreed with it. I'm going to do nothing about it.
Edinburgh
Birling: (To the tune of "Cwm Rhondda") Bread of heaven, bread of heaven, yum yum-yum-yum-yum-yum-yum! Bread of heaven, here I come!
Fitton
Martin: Well, we can sit in the plane, or we can sit in the rain.
Douglas: Can't we sit in the car or sit in a bar?
Martin: Douglas.
Douglas: I'm sorry, I thought we were staging an impromptu tribute to Dr. Seuss.
Gdansk
Carolyn: This is my son Arthur, and I promise you he couldn't hurt a fly...
Arthur: Thanks Mum!
Carolyn: ... because the fly would outwit him.
Helsinki
Carolyn: Oh, my goodness! Well, you certainly have surprised me with a cake.
Douglas: Thought we might.
Carolyn: Perhaps what's most surprising about it is that it's a fishcake.
Ipswich
Martin: I've had one. One is the correct dosage of quiche for the adult human male.
Johannesburg
Douglas: Carolyn, you're really not helping.
Carolyn: I know! I'm not trying to.
Kuala Lumpur
Carolyn: (Pretending to be a passenger) It means I'm gluten-intolerant.
Arthur: Well, I'll, I'll try not to be too gluten annoying.
Limerick
Martin: Is this the famous Admiral's pie?
Arthur: Yep.
Douglas: The admiral's not a fussy eater, is he?
Molokai
Douglas: You took my Petrus '05, and you ... mulled it?
Newcastle
Martin: (cabin address) So, we should be taking off in ... about an hour.
Carolyn: (shouting from the cabin) Martin! What have you done now?
Martin: (cabin address) So sorry about the delay – which is not, incidentally, because of anything I've done now.
Ottery St Mary
Arthur: Well, I was the one who thought of putting an otter in the fridge!
Paris
Arthur: Can I tell you in my own words?
Douglas: Who else's words had you planned to use? Winston Churchill's?
Qikiqtarjuak
Arthur: Bears! Bears, bears, bears, bears! Polar bears! Look! On the ground.
Douglas: Of all places!
Rotterdam
Douglas: I'm not being childish, but if I can't go to the Grand Prix I'm not being in the film.
St Petersburg
Arthur: Here you are, Skip. Nice hot cup of coffee.
Martin: Oh. (takes a sip) Ugh! It's cold!
Arthur: Nice cup of coffee.
Martin: It's horrible!
Arthur: Cup of coffee.
Martin: I'm not even sure it is coffee.
Arthur: Cup.
Timbuktu
Douglas: It's been a topsy-turvy sort of Birling Day, hasn't it? We flew away from the rugby; Mr. Birling got soberer and soberer; and Arthur ruined everything with his knowledge and erudition.
Uskerty
Arthur: You know, between the dames and the horses, sometimes I don't even know why I put my hat on.
Vaduz
Herc: I didn't realise you were in such thrall to royalty.
Carolyn: I don't give two hoots for royalty!
Herc: I think you give four or five hoots.
Carolyn: I do not.
Herc: And not just any old hoots: low and reverent hoots, like an owl at a Jubilee.
Wokingham
Arthur: I've brought Boggle, Guess Who?, Connect Four and Kerplunk.
Wendy: Are they ... rappers?
Xinzhou
Arthur: It's not "Have a banana", it's "'ave a banana!" - like the song!
Carolyn: What song?
Arthur: The "'ave a banana!" song. I don't really know it, except for one bit.
Douglas: (sings) Let's all go down the Strand.
Arthur: Are you alright, Douglas?
Yverdon-Les-Bains
Martin: ... but it's not brilliant for anyone else, is it?or:
Arthur: Oh, don't say that, Skip. The Swiss guys'll get used to you!
Martin: I'm like a capsized duck.
Zurich (Part 1)
Theresa: Was that the time Martin landed with one engine?
Carolyn: That's right.
Theresa: Yes, he's often told me that story.
Martin: Not that often.
Theresa: Quite often.
Zurich (Part 2)
Arthur: Don't worry Skip - Douglas always saves us. Like remembering the brake pads.
Martin: That was me!
Arthur: Well, yeah, but you were being Douglas.
OK. Bye.