I started reading fanfiction around -01, became a ff.net regular circa -03 and registered -05. I read an insane amount of fanfiction and it really piles up over the years, so I've read a lot. You won't find everything in my favorites since I had to do regular purgings back when only 250 favourites were allowed, but it holds quite a good selection of fanfics.
Prince of the Dark Kingdom; an AU that is original, well written, fascinating and absolutely brilliant. WIP
Dynasty; a dark Luke Star Wars fanfiction. Elaborate, intriguing, and a must read. COMPLETE
Altered Destinies; time travel to forties, unique & well written. COMPLETE (the sequel is unnecessary, not good and abandoned as well)
Botosphere (author); the best transformers fanfiction. COMPLETE & WIP
Make a Wish; hilarious. COMPLETE
Blood Magic; the best severitus there is. COMPLETE
Dragon and Angel; an old beloved DMGW fic. COMPLETE
Browncoat, Green Eyes; an excellent Firefly/HP crossover. COMPLETE
Meifu's Gate; a Bleach fanfiction series about Juushirou's and Shunsui's beginnings. COMPLETE
Lomonaaeren (author); lots of great DMHP COMPLETE
For people who spend WAY too much time on this site! & GASP! It's Harry and Voldemort together!; the two best C2s out there.
Real life stuff I recommend:
Neil Gaiman (everything, except some of the movies)
Raymond E Feist (everything, including the ones written with others)
Jim Butcher (both Dresden and Alera)
Terry Goodkind (Sword of Truth)
David Eddings (not the newer stuff and the non-fantasy)
Robert Jordan (not Conan, but Brandon Sanderson's present/future WoT books are included)
Bleach, Fullmetal Alchemist, Nurarihyon no Mago, Kuroshitsuji & Skip Beat
and much more.