I purchased the Yinlips YDPG16. Mainly due to the fact that it doesn't look like a PSP, I hate that with a passion! All in all it's a very decent console, not too cheap feeling, my biggest gripe is the touchscreen. It doesn't respond too well to finger tips, a hard tipped stylus or even your finger nail work much better. Qbertaddict did some benchmark comparisons between the G16, the G18 and the JXD S601. The G16 came out on top so I'm very happy I chose this model.
N64 emulation is pretty good, depending on the game there are slow downs and other graphical glitches. I havn't tried oc'ing past 1.2ghz yet but I'm pretty sure it can go a little higher. The usuals, Mario and Zelda, run fine but the only other game I've played for more than a few minutes was Sin and Punishment and that was damn near perfect from what I could tell.
Thinking about picking up one of these Android consoles?