Sachin Tendulkar has been the most complete batsman of his time, and arguably the biggest cricket icon as well. His batting is based on the purest principles: perfect balance, economy of movement, precision in stroke-making, and that intangible quality given only to geniuses, anticipation. If he doesn't have a signature stroke - the upright, back-foot punch comes close - it is because he is equally proficient in each of the full range of orthodox shots (and plenty of improvised ones as well) and can pull them out at will.
Though he has adopted a noticeably conservative approach in the last quarter of his career, there are no apparent weaknesses in Tendulkar's game. He can score all around the wicket, off both front foot and back, and has made runs in all parts of the world in all conditions.