the chain with the most work behind is the valid one correct? so suprnova is probably your safest bet?
not if it's being rejected by the network.
which it apparently is
I mean we should wait ZENdevs explanation. Currently ZEN blockchain is unstable and seems to be forked. Just wait oficial response

I'm in the dev channel and can tell you Suprnova's shares are being rejected by the network. I'm sure he will fix it but right now none of his blocks are making it to the network.
...
heres' an explorer. currently not showing suprnova blocks
http://luckpool.org:8003/