I went with iBasso, though I’d go for the DX160 for an all in one solution or the DX220 if you want more power and amp swapping options (which is why I chose it). Battery life on the DX220 is OK, but certainly, it’s the weakest point.
a lot of folks like the Fiio, it has plenty of power, and good reviews. KANN is relatively huge, and only really necessary if you want to drive big, harder to drive headphones.
sony’s newest (ZX507) may also fit the bill provided you don’t want to drive really inefficiënt headphones, though if only get it if you don’t live in the EU (due to idiotic volume caps that limit the power output).