lotrfanfiction.com used to have some fairly decent LOTR fic. I think it's fallen from grace a little since I was using it regularly but Spiced Wine (I think that's the write penname) had some pretty intense fics that people seemed to love. My stuff is still up there (under Lira_of_Imladris) - it's badly written but it's mostly 10th Walker and girl-falls-into-Middle Earth. The Lira's Lies series at least.
As for other good fics, "The Search" and "Along Came a Spider" by Jay of Lasgalen were awesome. She has an epic headcanon for Elladan and Elrohir (no slash). White Wolf wrote really great friendship fics with Legolas and Aragorn. Gemini Elf used to write cool stuff too. Those can all be found on the aforementioned website. Actually, here's a
link
Hope that helps
mrgreen