Yep, gotta agree with Brian Keene's The Rising and City of the Dead but don't forget about his novel Dead Sea either. Stephen King's Cell is great. H.P. Lovecraft's short story Herbert West: Re-animator. You should also check out Joe McKinney's Dead City, Apocalypse of the Dead, and Flesh Eaters. Jonathan Maberry's Dead of Night and Patient Zero. John Skipp edited a great set of zombie story anthologies called Book of the Dead, Still Dead: Book of the Dead 2, and Zombies: Encounters with the Hungry Dead.