One of my favourite toylines (Cloudees) are blindbox only, but very easy to cheat. What I didn't like was how hard some characters were to find - I am still missing a bunch, unfortunately.
I don't really care for blindbag/box otherwise. I would like to get the sylvanian babies ones, but I don't know how easy those are to cheat (tbf, I haven't looked into them, because I haven't found them anywhere). I would also get into mixlings, but they're very expensive here.