Chelsea Handler paid tribute to Rob and Michele Reiner during her Critics Choice Awards opening monologue … calling Rob the “nicest guy in Hollywood.”

Handler starts off the tribute Sunday night by saying “Anyone who ever spent time with Rob Reiner knows that the minute you met him, he felt like an old friend when you were in a conversation with him.”

The comedian notes how present he was and that he was focused, funny, and says “he would ask you tons of questions, whether you were discussing politics or film or the latest beauty trends.”

She continues to call Rob and his wife Michele “tireless in their efforts to so many important causes” saying it all stemmed from one basic idea … “decency and that we should all look out for each other.”

CH ends the heart-touching shoutout with “I think we can all agree that we definitely need more of that. So let’s use tonight as a reminder of that decency and as a reminder of everything Rob and Michele represented and fought so hard for.”