You can always judge by designs. That's what I did. Never played Gen 8 but I still don't like any of the full starter lines. Base forms are cute, but that's it.
Gen 1 - Charmander
Gen 2 - Cyndaquil
Gen 3 - Treecko
Gen 4 - Turtwig
Gen 5 - idk i dont really like any of their full lines
Gen 6 - Froakie
Gen 7 - Rowlet
Gen 8 - dont like any of these either
Out of these guys, Treecko, Cyndaquil, and Rowlet are my top three faves.