The song is done in bar chords and Glen Hansard wrote it after his niece told him 
that his music was depressing.
I couldn't find the chords so i looked at all of the different video's on youtube 
and i then got the chords by looking at the fret board and listening.Enjoy

Am:                Dm:               Em:
E[---5---]         E[---5---]        E[---7---]
B[---5---]         B[---6---]        B[---8---]
G[---5---]         G[---7---]        G[---9---]
D[---7---]         D[---7---]        D[---9---]
A[---7---]         A[---5---]        A[---7---]
E[---5---]         E[---5---]        E[---7---]

 intro: Am  Dm  Em 

VERSE 1:
Am
I'm the banana man, I go uppa that tree,

Dm                    Em
I go downa that tree, I go home for me tea

Am
I'm the banana man, And I drink me Coca cola,

Dm                             Em
And I play me rock'n'rolla down by the sea

CHORUS:
Am              Dm      Em 
Everybody likes bananaaaaa's oooohh

VERSE 2:
Am
I'm the banana man, I go uppa that tree,

Dm                    Em
I go downa that tree, I go home for me tea

Am
I'm the banana man, And I drink me Coca cola,

Dm                             Em
And I play me rock'n'rolla down by the sea

CHORUS:
Am              Dm      Em 
Everybody likes bananaaaaa's oooohh


Banana ah   banana ah bannnnna

Back to intro :AM   Dm  Em (x2)
OUTRO:
Am              Dm      Em 
Everybody likes bananaaaaa's 

AM              Dm      Em

Am              Dm      Em 
Everybody likes bananaaaaa's


Enjoy :)

来源：www.ultimate-guitar.com