If you want to add credibility to what you say about yourself, tell the interviewer what other people have said about you. The best quotes are not words that others have said about you to you, but about you to others. The best way to provide this information is to quote the other person, referring to yourself in the third person:
"My boss always said that if something needs to get done, give it to Jane and you know it will not only be done right away, it will also be done right."
"My professor once told my academic advisor, 'Tim is the one person I can continuously count on to give a 110 percent effort in every class.'"
"My coach called me 'The Dave' and coined the phrase, 'Give it to The Dave' when he had a game that needed saving. Even now, after I'm no longer on the team, he still uses 'Give it to The Dave' as his way of saying that it's time to put in the closer to win the game."
When you can quote what others have said about you, you have elevated the view of who you are to the shoulders of others. From that vantage point, your value increases substantially. Take note of what others say about you. And be ready to quote the quotables.