There is a similar thread for the Japanese language in the 'General Japan Talk' section so I created one for the Korean :D The title speaks for itself!
Well, mine are...
Aigoo
I really like it when the characters in a drama say this. I myself say it sometimes when something goes wrong :P
Yah!
The Korean alternative for 'Hey' or 'Oi'. I guess girls say it the best; like in: "Yah! Are you dumb?", "Yah! Who do you think you are?" xD
[i]Annyeong, Komayo and Mian heyo[i]
Basic words for 'Hello, 'Thank you' and 'I am sorry' respectively. I like the way they are said, like 'Annyeong' is usually said in rhythm by some cheerful, over-friendly sort of characters.
For now I can only remember these. I'll post some others if I can remember them later.
Let's hear from you guys :)