I started with 1942, which I consider one of the best BFs. The expansion packs for it were meh, but secret weapons was pretty interesting for a little bit. BFV was REALLY fun, if you like the BFV graphics and vegetation, but want to play on 1942 with that, check out the BFV WWII Extended mod. Its the same game as 1942 just with the BFV engine.
Bf2 did a few things to imrpove upon the franchise. They added the commander, squads, VOIP, and more weapons. However, they went backwards with all the glitches they had (and still have) and the 1000000 hour long load screens.
Now this brings up to BF2142, the most recent installment in the franchise. They got a couple of things right and somethings really off in here. Lets start with the good: Highly customizable classes and load outs, tons of quick unlocks, balanced infantry classes. Another good idea was the Titan gameplay mode. I loved this because it focused the combat in one area and it became really intense with 64 people fighting over something the size of a cap point. However, the vehicles in 2142 were way unbalanced. If you got a mech with a supply crate, you would never die. Players could barely kill them unless they did suicide demo charges. The AT players didnt carry enough munitions to be effective against any vehicles. But atleast they fixed the long level load times.