I'm endlessly trying to be more minimalist (though there's definitely a point of diminishing returns). I know exactly what you mean, OP, about having too much space and needing to fill it. I moved from a larger apartment to a smaller one, but the smaller one is laid out better and has actually resulted in my buying new furniture to fill it, which is frustrating. Even now it feels a bit empty and I think about additions for a while before the sense gets knocked back into me.
My big thing is digital > physical. I have awful vision (even corrected) so paper books are a pain for me, which makes it much easier and much, much more enjoyable to donate my paper books and stick to my Kobo and to Overdrive. I own maybe a dozen DVDs, which I should really toss, and a few signed CDs (the signatures are the only reason they stick around), but basically, if I feel the need to own it, and mostly I don't, it's digital.
I'm trying to digitize all my personal paperwork now, which is scary (there go 7 years of bi-country tax documents into the shredder!) but pretty damn freeing. Who needs a filing cabinet when Evernote and Google Drive exist?
All of this said ... I still end up owning a lot of stuff. It's a work in progress. Have y'all tried the 333 project? I'm loving it. I pulled a couple of things out of my winter box over the course of the season, but only a couple, and the rest are getting tossed or donated when I switch to the summer wardrobe.
Smartphone: Yes, and it's an Apple (cue the horror, I know)
Tablet: Nope, don't see the point
Laptop: Wonderful, hard-wearing tiny one
Desktop: No, although I use one at the office
Ereader: Yes, and a back-up. I spend hours most days reading.
Bike: Yes, and I've started biking to work again after several years of clown-car!
Car: Yup.
TV: I own one, but I've turned it on about twice in the last six years. I really need to get rid of it.