Now I want to preface this by saying all classes are obviously a wip but rogues feel really good right now to me honestly.
Cunning action is really nice for repositioning to an area with advantage for sneak attacks, particularly with a crossbow.
Theif's also get an extra bonus action. that plus everyone gets +attribute damage on off hands means thy do crazy damage.
A level 4 Thief with the level 4 two Weapon fighting feat will do 3(1d8+Ability score + Proficiency bonus) Per round, not including sneak attacks