i dont remember if this is from the original super mario bros or one of the others but 
the end credits song. this is 100% accurate


Riff A

e-----------------|
B-0-1h3---3p0-3p0-|
G-------0---------|
D-----------------|
A-----------------|
E-----------------|

Riff B

e---------3-|
B-0-3-0-3---|
G-----------|
D-----------|
A-----------|
E-----------|

Riff C

e-----------------|
B-0-1h3-1-3p1-3p1-|
G-----------------|
D-----------------|
A-----------------|
E-----------------|

Riff D

e-5p3-5p3-7p3!---|
B----------------|
G----------------|
D----------------|
A----------------|
E----------------|

play the song in this order

Riff A 4x
Riff B
Riff C
Riff B
Riff D 2x (second time no pull offs and slower)

and end with

e-5*-3*-5*-3*-7*--3*-|
B--------------------|
G--------------------|


Key:
h: hammer on
p: pull off
!: let ring
*: harmonic