Mordekaiser's joke - Not sure if he's saying "I like my womens..." or "I like my weapons...", LoL wikia says weapons but I always heard women.
Sivir joke / taunt - very quiet, had to turn my speakers up to hear them adequately.
Karthus joke / taunt - very quiet, hard to hear with ambient noise going on (requires turned up speakers, which makes everything else way loud)
Morgana joke / taunt - Mostly her joke, very quiet and hard to hear like Karthus.
Feel free to post others you guys feel could use a tune up.
(I honesty thought that's what he was saying for a good year or so--it's better that way.)