ok, this is my first tab

this is how i play it and it sounds correct to me.

tune it half a step down first :)

I haven't noted strumming pattern but if your reading this then you've heard the song 
can work it out cos your clever people =P

   D   A   B5   G  D?  <----- I'm not quite sure about the name of
                               this one but it sounds good
e|-2---x--------3---3---|
B|-3---2--------3---3---|
G|-2---2---4----0---2---|
D|-----2---4----0-------|
A|-----0---2----2-------|
E|-----0--------3-------|

Intro:
D, A, D?, A

Verse 1:

D         A               B5
  Now I know I messed up bad,
             G
  you were the best I ever had,
D            A                B5
  I let you down in the worst way,
              G
  It hurts me every single day,
D      A                   G
  I'm dying to let you know.

CHORUS:
G         D                 B5
  Now I'm here to say I'm sorry,
      A               G
  and ask for a second chance,
G                G                 G
  cos' when it all comes down to the end,
G                          D
  I could sure use a friend.

Verse 2:
D              A                B5
  So many things I would take back,
                G
  You were the best I ever had,
D                A               B5
  I don't blame you for hating me,
             G                      D
  I didn't mean to make you leave,

Pre-Chorus:
D                 A
  You and I were living like a love song,
B5                 G
  I feel so bad, I feel so bad now you're gone,
D                     A
  Now I know your the only one that I want,
B5                 G
  I want you back, I want you.

CHORUS:
G                           D
  Now I'm here to say I'm sorry,
                          B5
  and ask for a second chance,
                                      G
  cos' when it all comes down to the end,
                        D
  I could sure use a friend,
                           A
  Now I'm here to say I'm sorry,
                          G
  and ask for a second chance,
                  G
  cos' when it all comes down to the end,
                            G
  you were the best I ever had.

Bridge:
G                       D
  We fell in love for a reason,
           A
  now your leaving,

  and I just want you back,
G                      D
  so many things we believed in,
           A
  now you leaving,

  and words won't bring you back,
B5               A                 G
  I'll never let go of the heart i broke.

Pre-Chorus:
D                A
  You and I were living like a love song,
B5                     G
  Now I know your the only one that I want,
D                          A
  I want you back, I want you.

CHORUS:
G                         D
  Now I'm here to say I'm sorry,
A
  and ask for a second chance,
B5                                   G
  cos' when it all comes down to the end,
                        D
  I could sure use a friend,
                          A
  Now I'm here to say I'm sorry,
                        G
  and ask for a second chance,
                G
  cos' when it all comes down to the end,
                G              D
  you were the best I ever had,
D
  I can't believe that I through away all our dreams
A
  I can't believe now that you're gone how much you mean to me,
B5
  I feel so bad, I feel so bad
       G
  you were the best I ever had,
D
  I can't believe that I through away all our dreams,
A
  I can't believe now that you're gone how much you mean to me,
B5
  I feel so bad, I feel so bad
G (let it ring)
  You were,

  You were the best I ever had...


So, thats pretty much it, I hope you like it, comment if you wish. =]