Defaults < $500
Many borrowers have Telcos defaults. Most lenders will ignore these or most defaults under $500 if you have a reasonable explanation
Paid Defaults > 2 years
Some lenders will treat defaults that have been paid out more than 2 years ago as if they have never happened.
Some lenders are willing to consider overlooking blemishes on your credit record if you income is particularly strong and you have a good reason.
Bankrupts need to have been discharged. Even then the options are limited.