It's largely driven by state of mind. When I am happy and relaxed, Mendelssohn, Paganini, Mozart, Haydn, and certainly Bach. But whether happy or in a state of sullen distemper, the maestro always. He is always talking to us, saying brave and bold things, holding out the vision of a wonderful world that would be possible if only we let our natural selves come out and play. The others are all superb technicians, but they are speaking to themselves, and they are using orchestras as beautiful, unified instruments to create beautiful music, and presenting these to us. With Beethoven, it is a song that he sings for us, urging, begging, pleading us to come along.
Think of the Leonore Overtures - you know the three I mean - and what each variation says, the same thing but in different pitches, tones and urgency.
I used to be torn in two between the seventh and the eighth symphonies, but no longer; it's the ninth, all the way home.