Depends where you are, but I think [name_f]Madelyn[/name_f] is the most obvious.
I like [name_f]Madeline[/name_f] best too (and where I am, it would get the lynn pronunciation) but it depends if you mind correcting it sometimes
This is one of my top names, and I also prefer the -lyn pronunciation. I would probably go with [name_f]Madeline[/name_f] or [name_f]Madelyn[/name_f] because those seem like the most intuitive spellings to me. I have been told here that [name_f]Madeleine[/name_f] also gets you that pronunciation. I would introduce her with the -lyn pronunciation and I don’t mind correcting people.
I LOVE this name!!
Agree with this 
madelyn, although madeline / madeleine does look better to me as well, i would prn it as mad-eh-line 