With the purchasing of Star Wars by Disney, the new owners obviously wanted to do their own thing with it. The only way to accomplish that was to take out any previous additions to the canon that were not films. While I understand the need for Disney to reset and continue with their own stories, I am rather sad that the following Star Wars additions are no longer canon.
1. The Thrawn Trilogy
One of the best and first follow ups to the original Star Wars trilogy was the Thrawn Trilogy by Timothy Zahn. The writing is spectacular and the characters maintain a level of sophistication that draws the reader in. It is a mystery/adventure tale where our favorite heroes from the movies take on numerous challenges: from a mad Jedi Master, to a Vader-worshiping race of assassins, to an Imperial mastermind out to destroy all that the Rebels have built. Along the way, we meet completely new characters like the cunning smuggler and crime lord Talon Karrde, the ambitious politician Borsk Fey'lya, and mysterious force wielder Mara Jade. With mysteries, characters, and plots that pull you in, this trilogy is a must read, even if it is no longer "canon."
2. All of The Old Republic
Taking place thousands of years before the movies is apparently still enough to get kicked out of canon. But these series of comics and video games have such great writing, characters, and stories that they should be canon. From these series we get the wise-cracking fugitive padawan Zayne Carrick, the Jedi Master/Sith Lord Revan, and the hilarious assassin droid HK-47. Not to mention the lore each one contains of even older events that were considered canon at the time. And while these may no longer be canon and the video games are now a bit old, they stand alone very well even to this day and are worth a good look or play through.
3. The Solo Twins
This one is personal, as I grew up reading the adventures of Jacen and Jaina, the twin children of Han and Leia. Their stories move with the kind of pattern established by the Harry Potter series; they're fun and adventurous at first with certainty that your favorite characters will make it out just fine, but as time progresses, the twins age and the plots begin to twist and become rather dark. You start to worry for some of their companions and you even lose some along the way. The ending of their story is heart-wrenching which makes the climax all the more emotional for those who have read their stories since the beginning (like me). This is certainly a personal pick. The new canon does share some plots with these books, but they still aren't my twins.
4. The Legacy Series
Just as there are stories set long before the Star Wars movies, Legacy takes place 100 years after return of the Jedi. It follows the descendants of the heroes we know and love, which makes this addition to the Star Wars universe both familiar and strange at the same time. We get references to characters we knew before. We may see similar last names and nostalgic ships, but over all we are entering a whole new galaxy. The Empire is no longer just the big bad; it is now divided between the Sith and its rightful rulers, the descendants of Jaina Solo. The remnants of the New Republic are now just a straggling fighting force, trying to survive. The Sith now outnumber the Jedi and the last Skywalker is a drug addict bounty hunter with a destiny before him. This thrilling series of graphic novels has a good plot, great call backs to other lore, and an almost gritty post-apocalyptic feel to it that seems entirely its own.
5. Boba Fett Lives!
For looking like a total badass in Empire Strikes Back and in the extended universe, Boba sure got the raw deal when he got knocked into a giant space butt by a blind guy. So it was only fitting in later installments that revealed the Mandalorian bounty hunter survived his encounter with the Sarlacc and lived to fight another day. With that concept adopted, people began writing all sorts of great stories about the clone mercenary and his adventures out in the galaxy. There is still room for Disney to hop on the Boba Bandwagon, but until that happens, the lack of Fett stories makes this my #5.
Overall, I feel Disney has been doing well with their new canon. The Clone Wars have good story lines, Rebels has been very interesting, and The Force Awakens blew me away while the trailers for Rogue One have been giving me goosebumps. But while I may like what they have been doing, I wouldn't mind them adding some more of these great tales into canon.