Charles Kennedy's 10-year-old son Donald watched from the Commons gallery on Wednesday, as MPs paid tribute to his father who died on Monday aged 55.
And speaking in the Commons, Clegg said while Kennedy was a "formidable parliamentarian" he would want to be remembered first for his "devotion to his family".
"Much though he was wedded to politics all his life, I think Charles would have wanted to be remembered as a kind and loving father, brother and son first; and an accomplished politician second," the former deputy prime minister said.
"He had - and still has - that rare gift for someone in public life that when people think of him, they smile."
Tim Farron, who is seen as favourite to become the next Lib Dem leader, appeared close to tears as he looked up to speak directly to Donald in the gallery above the chamber.
"It's not what you have done, it is who you are. And Charles Kennedy was a very special man. Donald you should be really proud of your daddy, I am proud of your daddy, I loved him to bits. I am proud to call him my friend," he said.
Kennedy was first elected to parliament in 1983. He led the Lib Dems between 199 and 2006. However he lost his Ross, Skye and Lochaber constituency to the SNP's Ian Blackford in last month's general election. He was found dead at his home in Fort William.
In the Commons today, Cameron said Kennedy's "character and courage inspired us all" and praised his "warmth and good humour". The prime minister also noted Kennedy's "great loyalty" to Clegg - despite his decision not to endorse the Conservative-Lib Dem coalition. "At his best he was the best that politics can be," Cameron told MPs.
Harman, who is serving as interim-Labour leader, said Kennedy's example showed that devoting a professional life to politics could be a "honourable not an ignoble thing".
And she praised his decision as Lib Dem leader in 2003 to oppose the Iraq War. "He disagreed with the decision to go to war in Iraq and he was right. But he never felt the need to denigrate those of us who got it wrong," she said.
Harman added: "I remember when he first came to this House, aged only 23, a golden boy from the highlands, he shone in this chamber. He was elected so young and it is a tragedy he has died so young."
In his tribute, Clegg also highlighted Kennedy's leading role in opposing Tony Blair's push for war in Iraq. "Just because that may seem an obvious thing to do now, it was not at the time," Clegg said.
"Charles was often a lone voice in this House, standing up against a consensus in favour of war on all sides. The fact that he was proved so spectacularly right is a tribute to his judgement and his intuitive common sense."
He added: "Our liberal political family has lost one of its most admired advocates. British politics has lost one of its best storytellers. This House has lost one of its warmest wits and most loyal Parliamentarians.
"If we could all carry ourselves with a little more of the honesty, wisdom and humility of Charles Kennedy, politics would be held in much higher regard than it is today."
John Bercow, the Speaker of the Commons, opened the tributes by emotionally describing Kennedy as the "boy next door" politician.