If you're looking at 60% boards and want customisation options, there is only one choice: Poker II.
1. It's programmable so you can remap the Fn layer to your liking or even program all the Fn or Pn layer keys as game macros. You can even reprogram the main layer, so you can create any character layout you like or program the Pn layer to include gaming macros on some keys (Q, E, R, F, etc.), normal characters on others (WASD for instance) and then switch to the Pn layer when gaming.
2. Comes in backlit or non-backlit. Non-backlit version comes with nice thick PBT keycaps and just needs LED's of your choice soldered in to become a backlit version.
3. Completely standard layout = any keycap sets will fit.
4. Lots of aftermarket cases and plates made for it.
The V60 is quite nice, too, since they adjusted the design to fit Poker II cases, so at least it will fit most aftermarket 60% cases. Ducky Mini is "least" customisable since it won't fit any aftermarket cases. The biggest difference between the Poker II and the others is the programmability and it's a big difference IMHO.
If you don't care about the programmability or changing the case, then choose by switch type and aesthetics. I think they're all high quality boards. The Ducky Mini may feel a little more solid than the V60 due to it's heavier case.