I'm not entirely sure what classifies as an oldie, but I really must emphatically recommend ANY story by The Gorn. Her stories are still archived at Annesplace.
Also, I think I'd better recommend "Haunting Eden" by Lynn M. It's one of the great classics on the archive, although only the first part is finished and Lynn doesn't seem to want to upload it onto the archive until Part Two is finished as well. Which is a pity because it's a Kerth Winner if I ever saw one. And yes, I'm completely obsessed with it. Sue me!
You wanna great big angsty read? Try:
1. Masques by Labrat (So much for being a has-been, Labrat! wink )
2. Rage by Lynn M (The nFic version is the best, though)
3. ANYTHING by Yvonne Connell. The lady eats FoLC arteries for breakfast.
Also anything by Shayne Terry. She's really that good!
4. Near Wild Heaven by Kaethal. Pity the sequel isn't finished yet...
5. Heavens Prisoners by Demi and Kathy. One of my all-time favourites!
Pity you aren't asking for newer fics though. I'm thinking of a new author who's definitely God's gift to the nfic archive these days...(Guess who!)

“Is he dead, Lois?”

“No! But I was really mad and I wanted to kick him between the legs and pull his nose off and put out his eyes with a freshly sharpened pencil and disembowel him with a dull letter opener and strangle him with his own intestines but I stopped myself just in time!”
- Further Down The Road by Terry Leatherwood.