This is what I have so far. Not that much but I'm working on it! Already saw all eps of season 1 and 2 and now I'm going to rewatch for quotes! :D
season 1 episode 1 (Everything Change)
Andy: I walked, I bloody walked!
Gwen: Oh, you met him?
Gwen: You catch aliens? You are an alien catcher?
Jack: That is so welsh! I show you something fantastic, you find fault!
season 1 episode 3 (Ghost Machine)
Owen: Found him! … He's in the phone book!
Owen: I'm not gonna worry you. I'm gonna bloody kill you!
Jack: Alien of course. … Looks like Toys R Us!
Ianto: I believe a state agent pronounce it sploe!
Bernie: Are you going to arrest me?
Jack: No we are not the police
Bernie But I robbed that!
Jack: I know
Bernie: And you gonna rob it back of me!
Jack: So call the cops!
season 1 episode 4 (Cyberwoman)
Jack: Ianto I need to hear those beautiful welsh vowels!
If anything is wrong, please tell me! Thank you! :)