The current best Battlefield. Its atmosphere is unbeatable and it retains its crown now that BfV has lost support for new content.
Being a long time player I was originally no fan of the WW1 setting but having returned to the game in 2020 it still remains the undisputed best historical BF game since 1942. This has only been increased by the failure of V which, whilst overhauling shooting and movement mechanics, was shallow in terms of content. V did not come close to achieving what 1 did in terms of immersing the player in feeling like they were part of a World War. Furthermore, the incomplete tinkering with V’s shooting mechanics (ttk, etc) and lack of variety leave it in a poor state in the long term.
Operations in 1 are titanic campaigns with historical vos and context given before and after to immerse the player, it by no means simulates WW1 but gives the player a highly cinematic and dramatic experience of a variety of fronts, its content feels fleshed out and thought out, it still feels fun to play although a period of adjustment from tighter more fluid movement of modern games is likely to jar at first. New players might struggle against vets with all the new equipment but if you like BF you will get caught in the loop and quickly find yourself satisfyingly able to take down maxed out players with all the weapons and gadgets unlocked - everyone is equal on this battlefield.
With V having failed to flesh out its setting after years of ‘content support’ and the penultimate updates leaving it in its unfinished state, it appears that for players seeking a historical world war battlefield this will be the obvious option for years to come. Great sound design, a distinct graphical style, huge variety of weapons from the period and, most importantly, a great class based gameplay loop. All of these things will keep 1 far more active in the long term whilst its WW2 sister struggles to attract dedicated supporters.