Way too many to count, both in WCW and WWE. Most memorable in WCW is his Man Of 1,004 Holdspromo. Every third or fourth one is an armbar. He even continues throughout the commercial break.
His final night on Raw (As of October 2010) had Jericho make a promo which called back the aforementioned list of 1,004 holds, by having Jericho list every wrestler he's ever beaten. But if he beat someone like Kevin Nash or Scott Hall, who has wrestled under several aliases, Jericho listed those names too, and if he beat one Villano, then he beat all five. He even makes sure to point out that he beat The Undertaker twice.
One of the more memorable in the WWE was when he "Ortonized" his challenge for the title: "Me! Want! Title! Match!"
Plus the interaction with Santino Marella directly afterwards, where Jericho would constantly get Santino's name wrong and Santino would get angrier with each error practically yelling his name at Jericho by the end. Here is the whole Ortonized challenge plus him meeting Santino.
Let the bodies hit the floor? How about let the boobies hit the floor!
One of his most memorable of these exchanges was, after Stephanie got some breast implants, Jericho tossed up two pictures of her profile on the Jumbo-tron, exclaiming "My my, Stephanie, how you've grown!"
"Thank you Stephanie, you're the breast! *beat* I mean best!"
A 2002 promo with Kurt Angle featured Jericho & Angle talking about how they didn't like Edge, with Angle stating the reasons why he didn't like him; Namely that Edge had long blonde hair, dressed like a rockstar & was Canadian - All three characteristics being shared with Jericho. Jericho just looks at Kurt like he's a complete idiot, before Kurt realizes this & says "Oh, but I like you".
In fact, his entire reign as WCW TV Champion was one of the funniest things in wrestling ever.
As WCW Cruiserweight champ, Jericho would refuse to accept that Dean Malenko beat him for the title and would air a promo of him in the library of congress trying to find a loophole or any way to reclaim his title (short of actually wrestling Dean again).
"Welcome to RAW is JERICHO! Ken Shamrock, now I know you consider yourself the World's Most Dangerous Man, but after watching your performance tonight, the only dangerous thing about you is if people watch your matches while they're operating heavy machinery. I don't have time to come out there tonight and introduce you to my Fists of Fury, but maybe on Thursday, on SmackDown!, I'll give you the distinct pleasure of getting down on your hands and knees and kissing the grime off my boots before I pound you unmercifully about your head and upper torso. So show up on Thursday, Junior, and I promise you you'll never - ever - be the same - again."
His 1/2/2012 return, where he worked the delighted Raw audience without saying anything other an almost-mocking "Yeah!" thrown in now and then, all while wearing an epic Cheshire Cat Grin. Likely a debatable entry, but it certainly counts upon repeated viewings, when you know what's coming.
On that same note, his first match back on 01/16/2012 featured Jericho teaming with CM Punk & Daniel Bryan. Jericho was the second man out & spent so much time playing to the crowd that Dolph Ziggler, Mark Henry & David Otunga all entered in that time span; and the kicker? Jericho's sole involvement in the match was to be tagged in, jump around & play to the crowd, tag himself out again & head to the back. Still playing to the crowd.
Chris Jericho meets Delirious.. This is the rare funny moment involving Jericho where he wasn't the funniest guy involved.
Chris Jericho once interviewed a portrait of Dean Malenko. Why? Because Malenko refused to do a promo with him, which caused the portrait. Chris mentions they both have the same level of personality.
Jericho's conspiracy victim vignettes were also pretty funny.
Near the end of the 2012 Raw Money In The Bank match, Jericho is primed to take the briefcase after knocking Miz down the ladder. Big Show suddenly rumbles up the ladder and stares down Jericho, who displays the funniest "Oh Crap!" face, frozen in fear, before being knocked out and dropping off the ladder like Wile E. Coyote falls off a cliff.
During a match between Dolph Ziggler and Alex Riley, he was commentating at ringside and then decided to make a Tout of himself and the match... only for him to capture Riley rolling up Ziggler for the win. What makes this funny is A) His over-exaggerated "WHOA!" reactions and B) His comment afterwards:
Jericho: "He worries about me not winning the big one, he can't even win the little ones. Alex Riley, who hasn't won a match since Methuselah was alive still beats Dolph Ziggler!
Jericho makes a surprise return at the 2013 Royal Rumble as the number 2 entrant. The crowd is happy to see him and as the match kicks off, the crowd starts chanting "YOU STILL GOT IT". Jericho response?
Jericho: I NEVER LOST IT, BABY
Reminiscent of the Santino Marella example above, we have this video of Jericho and Fandango/Fahhhn-Dahhhhn-Go
Really anytime Chris Jericho is interviewed in a WWE video, he's going to have a few of these. Of special note is his Ass Pull description of Parts Unknown in The Self-Destruction of the Ultimate Warrior.
His entrance at Extreme rules 2009 especially when people touch him.