It's true that it's a major difficulty for French native speakers when they learn English. (for instance desert vs dessert, refuse vs refuse, etc...)
I think most slavic languages have no stressed syllables, but nyggus for instance would probably give you more accurate info on this matter.
Italian has stressed syllables, most of the time one the one before the last (a
lievo, profes
sore) and it's a bit longer.
But it's easy as pie compared to Mandarin (Chinese) : it has five tones !
There's a file sound here (.ogg) :
http://en.wikipedia.org/wiki/Chinese_language#Phonology
Five different meanings for one syllable ("ma"), wow ! (wow, wow, wow, wow..)
Not for you if you sing out of tune...