Here is an infographic I put together (rather badly, I might add) of Damien Walter's list of 20 best young (apparently defined as 40 or younger) SFF novelists. The list appears to be a little UK-centric and has some curious omissions (a debut novelist over Sanderson, Rothfuss, or Tregillis, really?) but it's hard to argue with many of these names.
For those of you who like simple lists, copying and pasting, or hate pictures - here is the list in a more digestible format.
Lauren Beukes
WtS: Moxyland (or Zoo City)
WN?: The Shining Girls
James Smythe
WtS: The Explorer
WN?: The Machine
Hannu Rajaniemi
WtS: The Quantum Thief
WN?: The Causal Angel
Madeline Ashby
WtS: vN: The First Machine Dynasty
WN?: iD: The Second Machine Dynasty
Aliette De Boddard
WtS: Obsidian and Blood
WN?: On A Red Station, Drifting
Hugh Howey
WtS: Wool (Independently Published)
WN?: Wool (Simon & Schuster Edition)
Joe Abercrombie
WtS: The Blade Itself
WN?: Red Country (with a new First Law trilogy forthcoming)
NK Jemsin
WtS: The Killing Moon (or The Hundred Thousand Kingdoms)
WN?: Untilted Magic Seismology Project (USMP)
Saladin Ahmed
WtS: Throne of the Crescent Moon
WN?: Book II of the Crescent Moon Kingdoms
China Mieville
WtS: Perdido Street Station (or The City & the City)
WN?: TBA
Joe Hill
WtS: Horns
WN?: NOS4A2
Chuck Wendig
WtS: Blackbirds
WN?: The Blue Blazes
Seanan McGuire
WtS: Feed [as Mira Grant] (or Rosemary and Rue [October Daye #1] )
WN?: Chimes at Midnight [October Daye #7]
Robert Jackson Bennet
WtS: Mr. Shivers
WN?: American Elsewhere / City of Stairs
Carlton Mellick
WtS: Satan Burger
WN?: Village of the Mermaids
Catherynne Valente
WtS: The Orphan's Tales: In the Night Garden
WN?: The Girl Who Soared Over Fairyland and Cut the Moon in Two
Tom Pollock
WtS: The City's Son
WN?: The Glass Republic
Elizabeth May
WtS: The Falconer (Debut)
WN?: The Falconer
Francis Hardinge
WtS: Fly By Night
WN?: A Face Like Glass
Nnedi Okorafor
WtS: Who Fears Death?
WN?: Lagoon