This has been a very informative read. Thanks everyone, for all the details! I love the blurb about the astronauts' club "just getting off the ground", literally, lololol. And I agree with the premise that Clubs meeting at venues can liven them up, even if your Sim isn't in the gathering. Especially that knockabout Club--that could really give a Dive Bar some interest.
I always put all my Sims' extended families into Clubs with them. It may take more than one Club, but that way family gatherings aren't missing any aunties, uncles, or cousins, and they're really easy to start.
I also have one Young Adult lady Sim who has several single elderly ladies in a Club with her, and she takes them out to dinner once a week or so just to get them out of the house for a bit of socialization. She's a Good Sim, bless her fuzzy socks. I've just gotten the idea for her to convince her guy to make one for elder gentlemen. Then they can have the two Clubs meet at the same time to see if anyone hits it off. They'll have to sign a waiver absolving my Sims of any responsibility for woohoo deaths, tho. :mrgreen:
Also, another future plan is to make a Campaign Staff Club, meeting at a Coffeehouse, for my Sim who is a Politician as the OP and others mentioned, along with a rival group. I'm hoping he can make his speeches to the staff and tangentially the patrons of the Coffeehouse , thus avoiding those sad, empty seats in front of the podium downtown. At the very least, they will be ripe for the Vote Securing.