Personally I believe year 1 had the best operators.
Buck - The oldest dlc op and still has one of the highest pick rates in the games.
Frost - Has the highest win rate in the game because of how unexpected she can be.
Valkyrie - You can never go wrong with extra eyes.
Blackbeard - Still extremely powerful, being able to stop a headshot can never go underestimated.
Cap - Very situational but can single handedly win you games.
Hibana - A better thermite. One of the best weapon kits in the entire game.
Echo - Can buy you a ton of time. Also counters the rush meta and operators like Finka and Dokk.
Just my personal opinion, but I would get the year 1 bundle.