I don’t think a single pair of “dream headphones” exist for me. As such, I own multiple pairs and use them all. When I’m at the gym or work, I prefer to be able to hear what’s going on around me, sound quality is second to convenience, for which I own a pair of JBL Tune 205BT and Apple Earpods (in case the battery dies). When I’m at home, I usually prefer speakers, but if I have to be quiet, Skyping, or need to hear stuff accurately a semi-open design works best, like the VMODA Crossfade Wireless and/or M100. I have a pair of open back AKG K7XX, they sound fantastic and I know why people like them, but almost never use them anymore now that I’ve invested in a decent set of speakers. Are there better examples in each category, sure, but I really don’t want to pay extra for them, or I find them to not be as comfortable, $300 is a good ceiling for a good pair of headphones.
On the rare occasion when I want to shut out the world, I have an old pair of Sony ANC headphones, but the ANC algorithm in them isn’t great, so I was going to upgrade to a pair of XM3, but will hold off to see what materializes from Eve.
IMO, on ear headphones never make sense. You sacrifice a lot of comfort, to gain almost nothing in portability and absolutely nothing in sound quality. Bone conduction is interesting, but you pay a lot of money for the novelty, for little meaningful upside.