My sims don't go on dates, or extremely rarely. But if they do, Myshuno Meadows is my go-to place. Hardly any other sim will be interrupting, there's a kitchen and bathroom, AND there's a wedding arch if the sims are engaged.
I don't let them date much at all, though. I don't like the goals, they feel immature to me. I mean, tell jokes, get them playful bla bla bla. I'd rather have both sims live together before engagement/marriage. Typically I'll play a single sim and have a townie love interest move in while they are still "just" friends. No need to date when you live together.
