What is?

I favour random selection. You end up with a perfectly representative parliament.

That's not universally true. It will, eventually, produce a comically unrepresentative group and the time it takes for that to happen will depend on the size of the pool of representatives compared to the population.

Fifty representatives randomly selected from a pool of a 300 million has a high chance of being supermajority non-representative.

Ideally, sortition or direct democracy.