I like あれ？！ Often it goes along with something amusing happening so it always makes me laugh.
I also like ぐにゃぐにゃ which means "crooked", and you also use it if you had to take an indirect route to get somewhere with lots of turns- very common in Tokyo...
broken apart, なっとう (as in, the terrible food) and 臭い/くさい (the state of smelling bad)
It's used in reference to *really* smelly things, as in, they smell like natto. At least the Japanese are honest about what they eat, even if they claim to love it.
セクハラ... does that count? ^^;; I love it and don't know why. I call organic chemistry モレハラ after my classmates started making jokes about nucleophiles and electrophiles and molecular harassment. xD If that makes sense to anyone else on these boards...
As for actual Japanese words... I agree with those who have already said it - 時々never fails to make me smile. As does 昔話. On the other hand, I made the mistake of introducing my Japanese classmates to the term おかま, and it's now a constant joke in class (since the guys have a habit of reading メアリーさん’ｓ parts in the dialogue).
Also, I love their way of putting things together (like マイケル said with なっとうくさい), making words up (マクる - slang for eating at MacDonald's. Why? I don't know, but it's fun!) and shortening everything (アメフト、セクハラ、東大...). Sure, it makes it harder for me to have a clue what they're saying, but I love it anyway. xD
[quote author=ティムシ レーン link=topic=116.msg1984#msg1984 date=1240802990] あたたかい, because of how hard it is to say quickly, especially it's past forms... a bit of a tongue twister, lol...;) (あたたかくなかった） ;) [/quote] You're evil. I just spent the last full minute trying to say あたたかかった at full speed without slowing it down once first or typing it out to read it. That was [i]hard[/i]. xD It also reminded me of my おさななじみ last year at the 花祭り in San Fran, complaining about how she hated that it was so much harder to say "it's warm" than "it's hot". xD
I keep thinking I want to come on here and mention my recent affinity for... some word, which I can not think of for the life of me. xD Oops. (Though しかし is becoming a beloved word, because it's the only word I keep catching on my fansubs lately. xD)
もちろん！！！ Don't ask! I just love to say it with a serious face and whenever possible, pumping my fist. A solemn しかし and an enthusiastic よし are equally satisfying.
