Definitely into Lego here. Last larger set I built was the Fairground Mixer. 9 year old daughter just built the Haunted House to display above the TV for Halloween. Also, just picked up the Parisian Restaurant before it retires with VIP points. Still have my sets from childhood and let my kids play with them. They also play with my figures from when I was younger like TMNT, Star Wars and Ghostbusters. I never saved my toys for resale figuring my kids would get some enjoyment from playing with them(that doesn't mean I won't save theirs).
Luckily, Hollywood has run out of ideas for new films/characters and keep rehashing the same stuff from a lot of our childhoods and keep things relevant. Now you can share with them as well with Lego sets like the DeLorean, Ecto 1 and soon the Ghostbusters Firehouse HQ. Not sure how long their license for Ghostbusters will be for but the Ecto 1 should definitely do well once retired. It's a great build and the minifigures should be different from what will come with the HQ set(75827).
Hardest thing that I find with my kids and legos is that none of them agree on building. My oldest hates building sets with instructions and only builds freestyle(creates some incredible things too), my daughter only wants to build Friends themed sets or holiday themed sets with instructions, my 7 year old son only wants to build difficult sets with instructions(he's been building Lego 8 years+ sets by himself since he was three) and my 5 year old hates regular Legos and only likes to freestyle build with his Duplos and Toy Story figures. So, you get everyone wanting to do their own thing unless you trick them into playing a game where you all just sit around the table and take turns calling out something to build and then spend the next 15 minutes creating your best version of the subject matter. Definitely a fun thing to do.