Kind of like the others, the most common dates are restaurants. I also have a venue that is a combined movie theatre, bowling alley and bar with a small arcade in Newcrest. That's a good place to go to not have to worry about the weather. I've also sent sims to The Lost Garden of Healing from Romantic Garden. That's kind of an irreverent date in which they play in the fountains and listen to baroque music. Parks or museums are also common choices.
I do have a lot of community lots. Lately, I've gotten into a little bit of a rut of keeping sims in their houses when they have kids. I added a toddler-oriented park where the parents can flop into the kiddie pool and there are grills. That's a place I can send parents with toddlers.
Recently, I'm making myself work past that tendency and I'm starting to send them out a bit more with their kids. I'm also trying to send them on more varied dates but restaurants work well for that.