I'm a noob too but I've learnt a few things:
1. The Dingoo A380 is newer but nobody is making new emulators or apps for it so little or no community support other than Alien Grey making new firmware versions (much respect due). The GBA emulator is hit and miss, GB and GBC run at double speed and there is no quick, easy or even possible fix to this. The Genesis/SNES/NES emulators are all excellent out-of-the-box though, as is Master System/Game Gear
2. The Dingoo A320 sounds quite complicated to get working as you'd like it to but it is very well supported by the community and the forums are full of help
The Gamegadget is released this week from http://www.gamegadget.net
but will only play bought ROM's from its in-house marketplace. Yet to see, other than Genesis what it'll emulate but I think it's one to watch. I'll have mine by Thursday so I'll post feedback. It's out of the box ready, built in the UK so the support should be excellent. It's good to see some place where you can legalize the downloading of ROMs. I'm square in that fashion!
Other consoles, I'd have to leave that to the community