Chords:
A: x02220
D: x00232
G: 320003
A5: 577xxx or x022xx
A#5/Bb5: 688xxx or x133xx
B5: 799xxx or x244xx
C5: x355xx
C#5/Db5: x466xx
D5: x577xx or xx023x
D#5/Eb5: x688xx
E5: 022xxx
F5: 133xxx
F#5: 244xxx
G5: 355xxx
G#5/Ab5: 466xxx
E5 (7th fret): x799xx
F5 (8th fret): x81010xx

School:
Verse:
6:0 0 0 0h5~ 0 0 0h5~ 0 0 0 0 7
Chorus:
C5 A5 E5 G5
Bridge:
3:--------6----6----6---6/14
4:--------5----5----5---5/13
5:------------------------------
6:-0-0-0-0-0-0-0-0-0-0 x4
Solo:
I'm not really sure, just start with this:
2:3~3~3~3~
3:2~2~2~2~
improvise in between, and end with this:
3: 9-9-9-9-\-7-7-\-6-6-\-4-\-3-\-2~~~-----*---*
4:----------------------------------------------1/7/0

Drain You
Verse: A5 C#5 F#5 B5
Chorus: F#5 E5 x1 then D5 E5 (x8 I think) then a D5 then B5 A5 Ab5 (confused?)
Bridge:
|Distorted|Clean|
1:0000000-----0---
2:3333333---00---
3:2222222000----
4:33333330-------
5:0000000---------
6:0000000---------
Just screw around with the bridge a little and you'll get it!

Aneurysm:
Intro: F#5 C5 B5 A5
Verse: PM a clean B5 then a distorted D5
Chorus: F#5 C5 B5 A5
Outro (Clean):
2:3-3-3-3-\-4-4-4-4
3:2-2-2-2-\-3-3-3-3 and keep sliding until you get to the ninth fret.

Smells Like Teen Spirit:
Intro/Chorus:
3:------------3-3-3-------------6-6-6
4:3-3-3-x-x-3-3-3-6-6-6-x-x-6-6-6
5:3-3-3-x-x-1-1-1-6-6-6-x-x-4-4-4
6:1-1-1-x-x--------4-4-4-x-x---------
Verse:
1:--1
2:1--
Pre-chorus:
1:----1-----1
2:1-1---1-1-
Post-Chorus: F5 F#5r (play xxx3xx during the pause)C5 Bb5 Ab5 x2
Solo:
3:---8-10---8r-8~-6-5-6-5--------------------
4: 10-----6-------------------8 6 8r 8~ 6 5 x2 then,

4:6-5-6-5-6-5-6p5p3 x4

Been A Son:
Verse:
2:3 3
3:2 2
4:0 0
5:-----3-2-0
Chorus:
4:5 5 3 3 2
5:5 5 3 3 2 3 2 0
6:3 3 1 1 0

Lithium:
Verse/Pre-Chorus: E5 G#5 C#5 A5 C5/D5 B5/Db5 (the verses are clean and Kurt arpeggios some of the chords. The Pre-chorus is very distorted and I think kurt throws a few pick scrapes in between some of the chords.)
Chorus: A5 C5
Outro: B5 A5 F#5 G#5 E5

Sliver:
Verse: C5 F5 A5 A5
Chorus: A5 C5

Spank Thru:
Verse: A D G A G D
Pre-Chorus: D5 A5 F5 G5
Chorus: E5 G5
Post-Chorus: C5 D#5 A#5 B5 a bunch of times the G5 F5
Solo: If anyone has the solo, please click here and mail it to me.

Scentless Apprentice:
Intro:
1:0 0 1 1 2 2 3 3 / 12
2:0 0 0 0 0 0 0 0
Verse:
4:4 4 0 4 0 4 4 4 0 4
5:4 4 0 4 0 4 4 4 0 4
6:4 4 0 4 0 4 4 4 0 4 x2 then 1:5~~~~~~~~~~~~(gradual bend)
Chorus:
5:3 3 3 3 3 / 5 5 5 5 / 7 7 7 7 / 8 8 8 8 /10 10 10 10 / 12 12 12 12 / 15 15 15 12 15 12

Heart Shaped Box:
this is a very hard song and it is my best guess
Verse:
3:----2-----------------------------
4:--2--2-----3------2--2---2---
5:0--------3---3---2--2---2---2
6:--------1-------0----------------

Chorus:
3:2 4~- 4~
4:2----3-------2--2\1--1
5:0----3-----2--2-----1--
6:-----1---0---------------

Solo:
2:--9~--7~----6 4-----6~6
3:7----5----4------6 4

Milk It:
Any sane person wouldn't try to tab this song. I only know the chorus and there is of course no guitar in the verses.
Chorus: Ab5 Eb5 G5 G#5 E5 (this chord progression is tabbed out and a lot less confusing in the tab for the in utero album.)

Negative Creep:
Verse:
6: 0 0 / 12 0 0 0 0 12 \ 0 0 / 12
Chorus:
5:-7-7-5-------------5 8 8 5
6:--------4-4-4-7-7-----------7

New Wave Polly:
Verse: E5 G5 D5 C5
Chorus: D5 C5 G5 Bb5

Breed:
Intro:
4: 4 4 4 4 7
5: 4 4 4 4 7
6: 2 2 0 2 5
Verse:
5:-11-11-11-11-11-11-11-9
6:-9--9---9---9---9---9--9--7
Chorus: D5 A5 C5 B5
Solo:
4:-11-11-11-11-11-11-11-9
5:--------------------------------------
6:-9--9---9---9--9--9---9--7

tourrettes:
Verse: F#5 B5 C5 A5
Chorus:
3: --4 3 4p3p0
4: 3
5: 3
6: 1

Blew:
Intro: E5 G5 A5 Bb5 A5 G5 Bb5
Verse:
2:--------------------8-----------------------------
3:--------------------7-------------------------8 8
4:------5-7-5-7-5---6-----5--7-5-7--------6-6
5:---7---------------------7-------------------------
6: 0----------------0---0---------------0 0 0 (something like that) x4
Chorus: this part is really fast. A5 Bb5 A5 B5 Bb5 A5 Bb5 B5 Bb5 B5