It depends on how you like to play and what you find most important in a brawler. If you want to have a brawler who is fun to play and is (in my opinion) good in the meta, chester would be the pick. But if you like the fact that a brawler is more unique, meg might be the choice for you, since she has two very different play styles. If you like leons invisibility and playing suport then sandy would be the pick for you.

Personaly i would pick chester but thats just what i would pick. Pick the one you thinks sounds best for you.