This is my first tab, of the track Vigil (by Jack Wall) from Mass Effect.
The underlying bass note that you hear at the beginning is a C and goes for the whole piece.
I'm pretty sure everything is 100%  correct, but feel free to voice any changes you suggest.

Tabbed by halbrd on 9/29/2012

~=held note

Guitar
e|--0~---------1~---3--1--0~--------------0~---1-3~----1-0---0---------|
b|-------3~------------------------3~----------------------3---1~--3~--|
G|---------------------------------------------------------------------|
D|---------------------------------------------------------------------|
A|---------------------------------------------------------------------|
E|---------------------------------------------------------------------|

e|--0~---1-3~---5--6--1~----0~------1--0-------------------------------|
b|----------------------------------------3~---------3~--------3-1~----|
G|----------------------------------------------3~--------3~-----------|
D|---------------------------------------------------------------------|
A|---------------------------------------------------------------------|
E|---------------------------------------------------------------------|

Lower notation (for bass, although it doesn't sound as good)
e|---------------------------------------------------------------------|
b|---------------------------------------------------------------------|
G|---------------------------------------------------------------------|
D|--2~---0~----3~---5--3--2~-------0~-----2~---3-5~----3-2-0-2-----0~--|
A|-------------------------------------------------------------3~------|
E|---------------------------------------------------------------------|

e|---------------------------------------------------------------------|
b|---------------------------------------------------------------------|
G|--------------2--3---------------------------------------------------|
D|--2~---3-5~---------3~----2~------3--2--0~---------0~--------0-------|
A|----------------------------------------------1~--------1~-----3~----|
E|---------------------------------------------------------------------|