Neville, speaking as a guest pundit during ITV's Champions League coverage, said Giggs's current form is as good as anything he's shown over his 20-season career.
"He's in a rich vein of form and there's a lot more to come," Neville said. "United have had some great players but Ryan's probably the greatest. He's won everything and he keeps producing performances like that."
Neville, who played 386 matches for the Reds, went on to anoint Giggs as a perfect role model.
"If you're a young lad breaking into the game then Ryan Giggs is the shining example of how to live your life right," he said.
"Why is Ryan still playing when he's almost 36? Because he does everything right - he prepares so well and that allows him to still deliver top-class performances.
"There isn't another left winger coming through at Manchester United - or in English football - that's as good as him at the moment."