Lacking Natural Simplicity

One of the things I'm trying to do this summer is to actually run and play more roleplaying games. I play every month or so with an adult group, though that has slowed down during the summer due to scheduling conflicts, and usually play once every month or two with my daughter and my niece and nephews, but I'd like to play or run more often.

I'd like to run a game for the kids every weekend, but I figure that will be difficult to achieve. We'll see. All but one of the kids is 11 or younger, and one who plays occasionally (depending on what game we're playing) is 6; the older one is in his mid-teens. I've been playing RPGs with them (and occasionally their parents) on and off for several years, starting with Fudge Bunnies & Burrows. Some of the kids have played when some of they were 5 years old or even younger; at that age I have the kids roll dice and handle all the rules work myself; it works great. When I run things I generally try to keep things age-appropriate for the youngest in the group. They've all played video games and are familiar with common fantasy and science fiction tropes from the games.

Over a couple of years we've played Big Eyes, Small Mouth (2nd Edition Revised) a lot, and Bugging', and D&D some, and Savage Worlds a lot. A couple of the older kids have run D&D and Savage Worlds adventures for me, one from a commercial module that was a present and another other using dungeons built with Legos and Lego figures as miniatures. We've played through BESM Dungeon and several Savage Worlds adventures (including some of the free adventures and some of the Savage Tales pdfs) and are working our way through a couple of D&D adventures.

It's hard to schedule time with all the kids together at the same time as I have free time, and there's no telling before hand when the next time we'll be able to play will be, so I tend to run adventures as short campaigns. I've never gotten to run a long campaign. BESM Dungeon and the currently running D&D adventure The Sunken Citadel (updated for 3.5E) have probably been the longest running games. I'd like to run Evernight or 50 Fathoms for them some time.

I'd also like to run more board games: I've still never played Settlers of Catan, despite having it for a couple of years.