Mainly prefer PC gaming, though I do own all 3 current gen consoles including the Switch, and an Android smartphone.
The Switch has a unique portable form factor that makes it stand out, and will likely get the most use out of me vs. PS4/Xbone once more games hit. PS4/Xbone though...they're just closed off x86 based PCs in a box only slightly smaller than my mini-ITX case PC. Exclusives are the only reason I own them (except Switch), but this gen fewer objectively exist due to most devs going multi-platform. Console makers usually have to pay for them, PC seems neutral ground, Microsoft is porting all their stuff to PC, and I'm getting more Japanese games ported as well. Also, hate paying for online play.
On the flip side, PC gaming has this continuous larger swath of exclusive content, due to games that only work well on keyboard/mouse, certain genres that just don't come to console, crowdfunded games that list consoles as stretch goals, and a chunk of indies that either stay on PC or release first on PC. More games in more genres means greater chance I find something interesting vs. consoles. I like higher fidelity graphics on PC enough to get good hardware, but it's less important to me than performance and inventive/deep gameplay. Too many sub-30fps console games this gen, while even unoptimized PC ports I can brute-force with hardware + lowering settings to net me solid performance. Literally the only game out of my near 1k Steam game collection I couldn't get to run a stable 30fps, was Batman Arkham Knight for months before patches made it possible. Also, most of my friends primarily play on PC anyway, mods are great and I like going back to old games.
Mobile gaming...I just don't indulge in. Sucks up too much battery, and I'd rather listen to music/audiobooks/podcasts or browse the internet. Not a fan of the limitations touch-only controls place on games, and hate how my already tiny screen real-estate is being taken up by own fingers. The Switch is the portable machine I've always wanted, joy-cons finally the decent portable game controller, and when at home it plugs into my big-screen.