I was led to listen to Beethoven's critically-acclaimed "Symphony No. 9". Well, this may be because I'm a novice regarding Classical music, but I didn't find anything amazing in there. Let's call it acquired taste, but I've heard dozens of Classical tracks that were superior. Let's say maybe I wasn't focusing much on the music (I was listening to it while browsing the web). Oh, and I even played it twice just to make sure, and still... nothing.

NOTE: the version I listened to is formally titled Symphony No.9 in D minor, Op.125 -- "Choral" and was played by Wiener Philharmoniker, Orchestra.