O'Neill told Villa's website: "I don't think Gareth would ever want to be saddled with the label of 'model pro', because people will always find some sort of blemish. But he has been terrific for us and his level of consistency is quite amazing.
"Gareth is definitely the sort of player the young lads look up to. Craig Gardner said he looks up to Gareth and I'm not surprised.
"It's a wee bit like the Manchester United players of old stepping into the side and seeing Bryan Robson there for instance or a few years later seeing Roy Keane.
"He's already made over 300 appearances for Villa. That is a phenomenal record at just 27. That says it all really. He's been terrific for this club. The very fact that he has played so much under each manager speaks volumes."