I love the cuddling in bed. One of my Sims couples does that automatically when they go to bed, and if one of them joins the other a bit later, they cuddle until they fall asleep, too. Come to think of it, the Lovestruck pack added a few very cute and fun animations, like when a Sim playfully pinches their partner's butt, the partner will react with a "Oh, you" gesture and a giggle... and I really, really love the making out animation you get once your Sims level up their romance skill. It's basically just very passionate kissing while standing.
Adults playing with kids is adorable, too, and I love the animation you get when an adult kisses an infant or toddler goodnight.
Oh, and for some reason, I think the chewing animation looks kinda cute on female Sims, don't ask me why 😁