A simple "I resign" will suffice.

From Attorney General Alberto Gonzales prepared remarks for the Senate Judiciary Committee:

“I apologize”
“I am sorry”
“could have — and should have — been handled differently”
“I made mistakes”
“I would have handled this differently”
“I should have done more”
“at times I have been less than precise”
“I misspoke”
“That statement was too broad”
“imprecise and overbroad”
“I regret that”
“management missteps”
“should have been more rigorous”
“should have been completed in a much shorter period of time”
“owes them more respect than they were shown”
“should have worked with them”
“I should have communicated the concerns more effectively”
“I should have informed them of my decisions in a more dignified manner”
“could have been handled much better”
“I want to apologize publicly”

Hat tip to Think Progress.