Definitely the Last Pilgrimage of Esquibeth. I loved it to bits. Next up would have been dancing with the maintenance bot in "We're Off to See the Lizard" and of course, meeting dear old Professor Jones in Axis Denyde
I guess it was the Rook woods quest even though it was difficult, I eventually succeeded. I got a kick out of the funny/angry faces my glitch made when she got her ass kicked trying and failing. That peter out peat quest was absolutely the worst even though I eventually succeeded. It was just painful to make everyone wait so we could get our speeds co ordinated.
I liked the Ghost quest. It was the last one I did and never would have if Wally McBeal hadn't posted about a Ghost hunt. It was fun to go with a group and explore the worlds.
@Treesa - Oh, I loved Rook's Woods. I managed to do it right before it got pulled for being buggy (helped me go up a level, too). I had to watch a Youtube video to figure out I could climb up the tree though lol.
I also really enjoyed the DNA quest- it was fun to see what streets my Glitch came from :) And Summer's Day, and the nearsighted-frog Eyeballery one... the list is long.
Unfortunately, I finished the game one ghost shy of a Faded Heart, though :P