I think that I must suggest you look at Sura Al Ikhlas , the Sincerity of faith (112), as it is suppose to be 'worth' 1/3 of the Quran. Then I do have some favourites that really hit home. I think they all interrelate but they are 2:255(and of course 2:256 but not directly related in the personal context mentioned), 24:35-46, and 20:5, tho' I think my understanding of this also rests on hadith and scholarly writings on the subjects. The first Surah (96) revealed to Muhammad through Gabriel is definately worth reading and is short. Muhammad did not receieve it all initially, as he ran down the mountain to get away from Gabriel before he had a chance to finish it, I think Gabriel managed to get to the fifth ayat at first attempt. Then of course there is the 'first' surah called 'The opening' which is recited in each prayer, and even may be recited over contracts.