Absolutely love this thread!! It makes me feel so awesome when I can read the word and know what it means without looking at the definition. Lol. All of these are ones that I myself also really enjoy saying and hearing, but my top favorites are:
aish- i totally say this, and yes, receive weird looks. lol
aigoo- read above. lol
sarangae- it just sounds so beautiful <3 lol
chincha- i fell in love with this after hearing hyun bin say it close to a billion times in secret garden. lol
There are more, but I may just share those later :)