I am on the grizzleheim quest and I usually just do it for money. But is it worth while, because the only reward is gold and trust me I got plenty of that.
I only fish for the chests to be honest. When Celestia fishing came out, the Celestian Sword (a retired Crown Shop wand) was added to the fishing chests there, and as I really wanted it, I fished there and got it.
The Beckett promo wands also used to be INCREDIBLY rare and hard to get, but they got added to Zafaria fishing chests. When that update hit live, the Elephant Graveyard was SO populated with people trying to get the wands.
Nowadays, I'm just fishing for Pirate101 music scrolls.