Emily Bindiger is a member of a vocal (a cappella) octet called The Accidentals. However, I first heard her name when I bought the first out of two soundtracks to the anime .hack//SIGN, composed by Yuki Kajiura. Actually, I didn't hear Bindiger's name at all; it was more like I heard the first of her vocal contributions on a track called "The World," sat with my mouth open for a minute (this was easy to do, as I was driving at the time and I think something had just hit my windshield), then eagerly looked through the CD's liner notes at the next red light to find out who this lovely voice belonged to (this was slightly more dangerous, but, I felt, worth it) - but who's really keeping track of these things?
Bindiger has a number of appearances across both .hack soundtracks, my favorite ones being the songs "Key of the Twilight" (a fast-paced, fiddle-driven song that is used almost too liberally in the actual anime as a sort of battle/action theme), "Fake Wings" (a simple song with acoustic guitar, layered vocals, and lyrics which I find somewhat unsettling), and "Open Your Heart" (beauty personified, or at least one avatar of such). Yuki Kajiura writes both music and lyrics for all of these songs.
Emily's personal section on the Accidentals' website credits her as having toured with "legendary singer-songwriter" Neil Sedaka for three years. She has also contributed vocals to the song "Adieu" from Cowboy Bebop. Though I thoroughly lack the vocabulary to describe her voice, I would attempt to describe it as highly melodic, gentle and relaxing in most places but sometimes revealing a bit of bite (see the song "Aura," again from the first .hack soundtrack).
Additional artists she has worked with can be found on her somewhat sparse web page, located at http://www.theaccidentals.com/emily.htm.