I remember we used to do these a long while ago, so lets bring this back.

Basically, we emulate Ash's team by randomizing Pokémon with http://wyncorporation.com/pokemon/

For Kanto, generate 12 Pokémon, with the last one being caught 30 times.
For Johto, generate 7 Pokémon, with the last one being shiny.
For Hoenn, generate 5 Pokémon.
For Sinnoh, generate 6 Pokémon, with the 6th being received in a trade for one of the previous 5. Plus, you can evolve one of the Pokémon you caught in a previous region.
For Unova, generate 9 Pokémon.

In each gen, make a League team, using six catches from anything you have until now. Then, you can make a PWT team, with fully a fully evolved team.

I'll start with two old ones I made