Lord of the Rings
I love the movies and the books of LotR equally, just in different ways. I've read The Hobbit and The Silmarillion but I've yet to get on to the Unfinished Tales. I don't tend to read pairings that aren't my top favourites (Legolas/Gimli, Merry/Pippin, Frodo/Sam/Rosie, Grima/Eowyn, Aragorn/Arwen and Aragorn/Boromir). I dig good angst and horror, though. Please note there's a lot of fanfic I've read and loved on lists but have yet to track down on sites.
Jump around : Stand Alones / Series
Breaking the Silence by Ashinae and nona
Terribly cute Legolas/Gimli.
Watermark by Gloria Lancaster
Nice, short Legolas/Gimli.
Thrown by Halrloprillalar
Nicely written, well in character Legolas/Gimli.
The Sea Has Its Songs by Paradox
Very pretty Legolas/Gimli.
A Surfeit of Honours by Halrloprillalar
Very amusing, cute and hobbity Merry/Pippin. The characterisation is just lovely.
A Bird and a Beast by Belinda
A few annoying errors, but overall really nice Legolas/Gimli.
A Conversation Upon Helm's Deep by MJ
Cute Legolas/Gimli dialogue piece.
Practicality by Adrienne
The Frodo/Sam sexy goodness.
Love Knot by jacquez h. valentine
Adorable Legolas/Gimli. Gimli's funny and they're just so very *them* in this story.
Untying Knots by Keelywolfe
Lovely bittersweet Legolas/Gimli with many nice details.
Cold Comfort by arachne
Kind of strange and rather angry Legolas/Gimli, that, nonetheless, I really like.
At the Closing of the Day by Twinkledru J.
Bittersweet Boromir/Aragorn/Arwen piece.
Beautiful by Celli Lane
Cute little story about Legolas' paradigm shift.
Beauty by Kate Bolin
Dark AU wherein Galadriel took the ring. Short and sharp.
Emblematic by Your Cruise Director
Interesting look into Aragorn's mind early on in the quest. I like the earthy details a lot.
Nor Iron Bars a Cage by FayJay
Bitter Grima/Eowyn.
Webs by RozK
Wonderfully written dark Shelob story.
Gold and Steel by Sofie K. Werkers
Interesting Grima/Eowyn AU that imitates Tolkien's style quite nicely.
Seeing by Darchildre
Simple but effective unrequited Grima/Eowyn piece.
Ice by kaydee falls
Strange but cool piece, looking through Grima's eyes at various things in his life.
Catch a Falling Star by Isabeau
A very cute pre-quest M/P. I have done the exact same thing as Pippin in this story.
The Sweet Purity Of Apples by Keelywolfe
Wonderful description and nice M/P UST.
Apple Sauce by Halrloprillalar
Merry and Pippin are such naughty hobbits. Very nice.
Barleywine by Ailei
Sweet and hot and silly and all the things good Merry/Pippin should be.
In a World of Strangers by Isabeau
Wistful, painful post-quest story that just works. I really wish there'd been something like this in the book.
The Talk by Cleo Calliope
Some good Pippin angst.
Kiss Me by Madelyn Scott
Pre-Quest Merry/Pippin with nice build up of sexual tension. Very nice, indeed.
Parental Consent by Honesty
Very funny Legolas/Gimli.
Echoes by Little My 
A gorgeous L/G story in the glittering caves. Supposedly a PWP, but really gorgeous, all the same.
Birthday Present by Bec
Icky Smeagol slash.
Last Night I Dreamed Again of Bag End by Baranduin
More really good Frodo angst.
Reclamation by Victoria Bitter
Edgy Rosie fic.
The Rose, the Thorn, the Blood, and the Moon by Halrloprillalar
Very funny Legolas/Gimli.
They Say About Elves by Brancher
Very cute, sweet, lovely Legolas/Gimli. It's just so pleasing.
Day For Night by mcee
Vampire hobbits. Really cool vampire Merry/Pippin, in fact. Dude.
Where the Shadows Lie by Anne Ellis
Deep Dark Frodo Angst.
Pebbles and Embers by mcee
OK, I'm not terribly fond of Aragorn/Legolas, but this is so damn cute.
Phantom Pain by Victoria Bitter
Everyone in the fandom has rec'ed this and with good reason. It just hurts.
Appleseed by Vissy
Pre-quest Hobbity gen. It's just adorable.
Crush by Cimorene
Really hot Merry/Pippin. This is, like, the defining M/P PWP.
Waiting For Courage by Cimorene
This is a beautiful Sam/Frodo and Aragorn/Arwen story and it's just so lyrical.
Don't You Lose Him, Samwise Gamgee by mcee
Sam angst. Aww!
Wraithcall by Elke Tanzer
Eep! Freaky dark Frodo!
Dancer by Lobelia Sackville-Baggins
Eep! Creepy Shelob fic.
Sallow by Slipstream
More freaky dark Frodo. Feel the angst.
Cabbages and Kings by Madelyn Scott
There's a lot of crappy Merry/Pippin fic out there, which makes Pippin act like a baby and the cousin thing come off as icky as it did in Wuthering Heights. This is not one of those stories, at all. This is really good Merry/Pippin. I love when people do my OTP well.
Inclemency and Incalescence by Essi
Nice and descriptive, but the angst isn't as overdone as it often is in these kinds of stories.
After Helm's Deep, After Pelennor and Post-Post-Pelennor by Amedia
The first two are bittersweet Legolas/Gimli missing scenes. The third is just hilarious.
The Folly of Starlight series by AC
It's Elrond/Legolas, but it's just so beautifully written, and has such gorgeous characterisation (including of Arwen) that I can't help but love it.