Hogan/Rock at WM18 is one of the most legendary crowd reactions in the history of the business, the Skydome in Toronto was electric especially when he Hulked up, the roof came off the damn place, they wanted Hogan to win that match sooooo bad. I'll never forget watching it live.
Hogan got a HUGE response from the crowd the next night on RAW in Montreal
And another HUGE reaction at Smackdown few weeks later (also in Montreal) They cheered so long WWE had to edit it LOL. They wouldn't let Hogan speak, every time he tried, they got louder, Hogan even gets emotional and starts to tear up.
Boy, those Canadians really love the Hulkster eh?, maybe that's another reason why Bret hates him so much, LOL.
As far as biggest/loudest pops go, I don't know where I'd rank those Hogan pops (they are very long, more sustained ovations vs a loud pop) but they gotta be up there with all the others that get mentioned, there's a bunch of 'em.
Austin helping Mankind beat The Rock for the title on Raw- Jan '99
Austin at Backlash 2000
Bulldog beating Bret at Summerslam '92 in Wembley
Bret's entrance at Canadian Stampede
Ultimate Warrior beating Honky Tonk Man at Summerslam '88
Hogan slamming Andre at Wrestlemania III
on and on...
You can debate that all day.
But I don't think I've ever seen anyone get the love that Hogan got from the Canadian fans at WMX8 and afterwards, that was crazy.