I think I better link to these, for the sake of completeness in this fic journal.
Title: Academic Eros
Rating: Mature
Pairings: Sherlock/John
Summary: It's John's last year doing theory at university before he starts training in a hospital. But to get there, he first has to pass the infamous Dr Sherlock Holmes' Biochemistry paper ...
Contains: teacher!Sherlock/student!John, Alternate Universe
Word Count: 47,464 (so far)
(
Sherlock was unmoving, eyes tracing over John's figure as if mentally weighing him up. "Well. You aren't as dull as I thought you'd be, John Watson. Feel free to drop by if you have any other questions.")
Title: The Loss of Flesh and Soul
Rating: Mature
Pairings: one-sided Sherlock/John
Summary: Five years after John Watson puts the murderous Sherlock Holmes behind bars, a vicious copycat killer emerges. A reluctant John is pulled out of retirement to seek the expertise of the only man who can help, a man who has developed an unsettling obsession with John himself. Crossover with Red Dragon/Silence of the Lambs
Contains: a murderous and cannibalistic Sherlock, Alternate Universe
Word Count: 8,585 (so far)
(
"You're remarkable," Sherlock suddenly whispered, lips right against John's ear. His breath brushed flushed skin. "I think I'll eat your heart.")