Fixing the other chords listed here, had a couple errors in it.  Depends on what version 
you listen to, but many of them are played in C.

For a little added spice, try this:

For C chords:
E------3---3------ | 
B------5---5------ | 
G------5---5------ | 
D------5---5------ | 
A----3------------ | 
E--------3-------- | 

Am :
E------5---5------ | 
B------5---5------ | 
G------5---5------ | 
D------7---7------ | 
A------7---7------ | 
E----5---0-------- | 

F :
E------1---1------ | 
B------1---1------ | 
G------2---2------ | 
D------3---3------ | 
A------3-3-3------ | 
E----1------------ | 

G :
E------3---3------ | 
B------3---3------ | 
G------4---4------ | 
D------5---5------ | 
A------5-5-5------ | 
E----3------------ | 

Solo in C major, keeping to tempo and the overall Celtic feel, but improvise all you 
want - pretty safe song.  Enjoy.

     C                    Am
    As I was a-goin' over Gilgarra mountains
     F                           C            Am
    I met Colonel Pepper and his money he was counting
      F                          C          Am
    I drew forth my pistol and I rattled my sabre
            F                        C           Am
    Saying "stand and deliver, for I am a bold deceiver"

    Chorus

          G
    Musha ringum duram da
    C
    Whack fol de daddy-o
    Am
    Whack fol de daddy-o
            C       G      C
    There's whiskey in the jar

    The shining yellow coins did sure look bright and jolly
    I took the money home and I gave it to my Molly
    She promised and she vowed that she never would deceive me
    But the devil's in the women for they never can be easy

    [chorus]

    When I awoke between the hours of six and seven
    Guards were standing 'round me in numbers odd and even
    I flew to my pistols, but alas I was mistaken
    I fired off my pistols and a prisoner was taken

    [chorus]

    They put me in jail without a judge or jury
    For robbing Colonel Pepper in the morning so early
    They didn't take my fist so I knocked down the sentry
    And I bid a long farewell to that cold penitentiary

    [chorus]

    Some take delight in fishing and bowling
    Others take delight in carriage a-rollin'
    I take delight in the juice of the barley
    Courting pretty women in the morning so early

    [chorus]