Having read widely I would say the greatest Jewish writer of the frum world of literature is
1. Rabbi Nachman of Breslov – his stories border on mystical fantasy and create amazing worlds full of beggars with super powers, lost princesses, evil cults etc.
2. The modern frum writers are somewhat limited by the publishing companies trying to keep the stories within halachic guidelines. Whilst the companies are looking for exciting fiction such as a John Grisham type thriller – the stories have to be filtered through a halachic filter.
3. Most of the frum thrillers really deal with one plotline – how a non frum person became frum because of a number of bizarre events that took place during their life. Explosions, natural disasters, illnesses, intrigue and crime are frequent in these stories.
4. In the non Jewish world, thrillers are also looked on as being the bottom of the literary pile. Its what sells and thats all. Their greatest writers – Frank Kafka (who was Jewish), Philip K. Dick, David Wallace Foster, etc were talented enough to be able to write stories that reflect their own thoughts resulting from their creative imaginations, life experience and feelings.
5. In the frum world thriller writers cannot create a story that shows you what it means to be living a frum life in the modern world. They cannot write what their battles are with sin and taavos(desires), living with poverty and hardship, nor would their publishers want them to. They are then less able to give a true picture of life but create an artificial one where everything works out well in the end. Besides the readers of these books are looking to be entertained and the publishers are looking to make money. Instead of they lived happy ever after with faith in G-d despite the hardship, we are told they lived happily ever after without any hardship!