Which Alt-Coin without ASIC is the best to mine?

[Tamilson]

at the end there will be millions of asic devices designed to  mine any coins with any algo.
best opportunity for manufacturers.

I have not heard that already there is a asic miner for Etherium.

There will not be ASIC for the Ethereum. Ethereum will be POS some time next year. So it is not feasible to design ASIC for ETH.

Also the Ethereum POW mining algorithm uses a lot of memory, which is more expensive to implement in ASIC.

I do not believe that there is an Ethereum ASIC out there. The hashing rate rise is mainly caused by the GPU farms.

I think so. There is shortage of the nVidia 1070 and 1060 and also the AMD RX 480 and 470. They are used for the mining.