I heard an interview recently on ABC Radio National with Zubin Mehta, the Parsi Indian conductor.
Mehta, asked about an orchestra's typical season, responded that Mahler - whose work has been one of Mehta's focuses - shouldn't be in everyday repertoire. By way of explanation, he said that into each of Mahler's symphonies, he had put everything he'd learnt up to that point, with the implication that it would be too dense for regular appreciation.
In talking about a typical season, the announcer opined that Mozart was something we could all listen to every day. Mehta moved quickly away from that, but felt that Beethoven's Eroica [Symphony No. 3] ought to be played every season.
We all have our musical preferences, and I've not listened to Eroica in great detail. But I wouldn't disparage the suggestion that Beethoven's 3rd could be listened to live at least once a year, with enjoyment and something to be gained from it each time.
My particular interest right now stems from the discovery that the second movement's theme provides the motif for a favourite piece of music of mine, Richard Strauss' Metamorphosen. I've been listening to Eroica today, but haven't been able to pick it out. Yet.