I hadn't seen the appeal of Delicious until I started using it a couple of years ago. I love being able to bookmark my favourite fics, art and vids all in one place. Also, the organisation freak in me loves the ability to use multiple tags on everything, so I can easily find anything I'm looking for. I could use my browser to bookmark things but I don't want to clutter my folders and subfolders of bookmarks that are already too many with stuff I've already seen/read. And although I save everything I like in my computer, I never used to know where I found a piece of art or a vid since I didn't save the links (only with fic I did that).

As for looking for new fic, I prefer searching on Delicious than browsing through LJ communities. In HP, I know where to find good fic (I never look for HP fic on Delicious), but in other fandoms I don't. I can search by tag(s) and look for certain pairings, or certain anything. And I can see how many people have saved something, their comments on it (if any), and that's proved very helpful to me for finding good fic.