It's beloved among the books. Saying it's as beloved as the big screen Original Trilogy is an exaggeration in the extreme. Apples and oranges.
If you want to talk novelized SW literature that's had an impact on the overall Lucas universe over the last twenty years then you might have a point. But saying the Thrawn Trilogy books are as cherished as The Empire Strikes Back?
[Will Smith] HELL, naw. [/Will Smith]
Tie-in novels are read by approximately 2% of the fanbase.
(this fact courtesy of Greg Cox
It may mean as much to them as the OT (just as many Trek novels hold as dearer place in my mind as the very best episodes and movies) but to the world at large? Nu uh.