Oh my god that fic.

Never Leave Fanfiction Lying Around, by Crazyroninchic. It has a Tv Tropes page, and there's a link there.

So, this is hilarious. It's set after the Lord of the Rings, and the characters come across and read a story called Tales of a Dream Come True, which is pretty much every LotR Mary Sue cliche mashed up into one story. Their reactions (especially to the Suefic versions of themselves) are uproarious. The only break with canon is that Legolas is still in Middle-Earth, but it's acceptable as the reason is so that he can be hilariously tortured by the Sue's romantic relationship with him (what else would the story be, if not a Legomance?).

Features Suefic!Legolas the lovesick pansy, Thranduil escaping out a window (he REALLY wasn't ready for the Suefic), and Sues outstaying the Suefic!canon characters at every possible point (much to the outrage of the real canon characters). Is a must-read.

Crazyroninchic also has a sequel to it where Starr's kid tries to atone for her mother's sins... by assassinating her.

It's a very entertaining story series. I remember in my younger years printing it out into a binder and taking it with me so I'd always have some Sue-bashing goodness to read about.

I think crazyroninchic also wrote "I Blame Iendil Ancawen Entirely"? Also a pretty good Sue parody, if ended a bit abruptly. Admittedly, it's not as parodic as Never Leave Fanfiction Lying Around, so...

I was really good friends with crazyroninchic back in the day, oh gosh. I even at one point wrote a tie-in fic approved by her where Starr, Celeste, and that darn faerie learnt the consequences of going to Middle-earth. It involved the Fellowship writing letters to Elrond begging him to send them corks for their ears because the Sue-song was so awful. Eledhwen made her first-ever appearance in that fic, actually! That fic served as the springing point for her backstory, where Starr and Co turn out to have been sent from a MS Factory and thus kidnap her...

Mine's not on FFN anymore. Don't bother looking. -wink-