1) we can't say standard.. we only say Classical or Dialect. 2) Khaliji(in the gulf area) is closer to classical. but maybe another dialect uses a classical word that's changed in the gulf dialect. 3) Ofcourse the egyptian dialect is the most well known dialect, coz of its most famous actors and movies and Media production in general

Hi Yoshi Hardy is right ...Egyptian is the most understood dialect in the Arabian world..and it's easy to learn and you will communicate with anyarab using it ...for the khaliji it's spoken in the Gulf countries but it's different from the modern and even the classical Arabic....there is no agreement about which dialect is closest to the academic Arabic .. ..there is some thing you should know ... in each country you will find different dialects so don't bother yourself ...in my country each region has its own dialect ...east...west...north and south but we all write the academic Arabic (العربية الفصحى)

It is recommended to study the MSA to be understood all over the Arab world because it is hard to tell which dialect is most close to it. Anyway, if you're a beginner learner, so learning either the dialect or the standard langauge would have the same degree of dificulty (as a beginner learner). But if you're intenting to go somewhere, that will require to learn their own dialect, yeah Egyptian and Levantine dialects are widly understood, but it would be difficult to communicate if for example you're planing to go North Africa. There are known to be difficult, but in fact they are not, as long as you're beginner in the whole langauge. But eventually, it is so hard to say which dialect is close to the MSA, cause around 50% of words of each is taken from the standard language, but the other 50% are different to each respective dialect. & Good luck

mar7aba good question when you study Arabic please you should study standard Arabic cause everyone here understand it well but if you need one dialect Libyan the most interest Arabic dialect cause it's very near

I can't really tell which dialect is closest to standard Arabic but the most understood dialect is Egyptian because a lot of Egyptian movies are shown around the Arabic world You can check this article : http://en.wikipedia.org/wiki/Arabic_language#Dialects_and_descendants