I stopped playing one year ago during the spring for a terrible accidental event. But I will tell you my favorites based on what I remember.
1. Desert Treasure-I died like a million times because of the dumb guy I forgot his name but he's the guy that drains your prayer a lot and he lives underground and like if you have your prayer turned off, he can do up to 28 damage. I liked this quest because it's challenging and it took me days to complete it. Fhareed was the easiest to defeat.
2. Legend's Quest-Challenging! I did it with a good friend of mine. At the end, where you defeat a demon, I got lucky because I had no food left and I just happened to walk in a glitched spot where the demon got stuck, but I could still hit it with close ranged weapons like the Silverlight and Rune Scimitar. It just stood there taking hits without attacking me. And my friend was just standing there laughing his head off.
3. Roving Elves-Never died and it took me 8 hrs to do in one day. It was fun killing that level 82 Moss Giant.
4. One Small Favour-Long!! But I managed. I like the reward.
My favorite reward out of all: Ancient Staff with the Ancient Magicks!
What are yours?