Methods are very elementary, but a good direction to third-party ranking system for the coins

https://www.coingecko.com/en

There is a write-up how to measure intrinsic value of a coin https://bitcointalk.org/index.php?topic=572090.0

Finally, a third-party ranking system based on electricity burning cost, development effort (code base), brand (??), popularity (??), innovation, adoption, liquidity can help.