Mine would be:
Classic- The Woman in White by Wilkie Collins- A man walking home comes across a young woman dressed in white who is frightened and needs to find a cab to get into town to the safety of her family. You help her. Then along comes another group who tell you the woman has just escaped from a mental institution and is very dangerous...does he tell them where she has gone, who is lying and who is dangerous....
A great, grabbing opening that turns into a thumping great read
Contemporary What is the What by Dave Eggers- A novel based on the true life story of a Sudanese boy who is orphaned in the civil war, escapes the attack and makes it on foot to the border and becomes one of the lost boys without a country living in a border camp, coping and trying to learn about life. Eventually sent to America where there is an even steeper learning curve...heartbreaking story of human spirit and also wonderfully written