KANSAIBEN (関西弁 - kansai dialect)
Kansai-ben takes up a large slice of even the Tokyo resident's mind. The comedians on TV speak it incessantly, three large cities (Osaka, Kyoto, and Kobe) speak it, and most Japanese accept the differences as quaint and interesting, just as most Americans think of Southern accents, and Londoners think of Northern accents.
Kansai-ben has many different variations (there are the lowly country variations like southern Wakayama Kansai-ben, and almost elitist, ultra-polite Kyoto-ben) as well as many different levels of depth. Some Kansai residents from Nara speak very little Kansai-ben, while people from Amagasaki speak a very strong and distinct Kansai-ben.
Kansai-ben varies from one part of Kansai to another, but here are some of the more common features.
The most noticeable difference is the substitution of the negatives -hen / -n or -mahen for -nai or -masen. (Sometimes only one of "-hen" or "-n" is acceptable in a particular grammar construction. For example, kawande mo ee (kawanakute mo ii) cannot be replaced by "kawahende mo ee".)
Hyojungo (Standard Japanese): Wakaranai. (I don't know) Kansai-ben: wakarahen / wakarehen / wakaran (note that when attaching -hen, the conjugation does not always follow that for -nai).
Also, while hyojungo uses "yo" for emphasis, many times Kansai-ben uses either an elongated "na" or "de".
Hyojungo: Natto wa tabenai yo. (I don't eat natto.) Kansai-ben: Natto wa tabehen de~.
Furthermore, when using "da", "datte", or "daro", many times Kansai people will substitute "ya" for "da". "Metcha" or "mutcha" is also substituted for words like very emphatic words like "cho" (Yokohama/Tokyo-ben) and "sugoi".
Hyojungo: Natto wa sugoku kusai, daro? (Natto is very smelly, isn't it?) Kansai-ben: Natto wa metcha kusai, yaro?
Many of the grammatical constructions have a classical feel to it; one can find many traces from older Japanese pronunciation: sabui (samui), hayo (hayaku), yuuta (itta)...
throw away: suteru ----> hokasu
exhausted: tsukareru ----> shindoi
nihongo resources - word list http://www.nihongoresources.com/language/dialects/kansaiben/wordlist.html
nihongo resources - grammar http://www.nihongoresources.com/language/dialects/kansaiben.html
the Japanese page http://www.thejapanesepage.com/kansaiben.htm