Sonny has a kid with Alexis and got her daughter Sam preggers
Brooke on B&B has kids with Ridge and Eric
Mimi on Days has a kid with Phillip and Rex
I am sure there are many others those are just off the top of my head.
My favorites from the 1980s in date order were Nikki's first visit to the Newman Ranch, Katherine's facelift, and Beth Maitland's Emmy winning episode. I would have included Victor and Nikki's 1984 wedding if that hadn't already been broadcast in 2016.
My favorites from the 1990s in date order were Neil and Dru's first meeting, Victor reveals he's alive to Jack, Shemar's first episode, Victor gives Nick a boxing lesson, Victor puts Nikki's makeup on while she's in the hospital, and I WILL CRUSH YOU!
I didn't really have any favorites from 2000-2005 and 2006-onward I skipped. I think Victor and Nikki's 2002 wedding was also a second time broadcast.