bf4 is a REAL sequel, bf3 is a blue tinted pile of trash
BF1942 - Silly, balanced, straight forward classes
BF 1942 Expansion Packs - well worth their price, interesting content and amphibious vehicles
BF Vietnam - Many weapon choices, many choices of heads and outfits, interesting weapon types, napalm, amphibious vehicles, mortars
BF 2 - Glitchy as hell, lacked co-op on release, broken hit boxes, good mods, wouldn't have existed if it weren't for the Desert Combat mod
Bad Company series - stuffty downgrade compared to the other games, tailored for consoles, ported to pc
BF 2142 - Titan mode, some changes were questioning like combining classes
BF 1943 - console only game
BF 3 - No mod support, No co-op, blue and grey tint, destructible terrain is a gimmick, over emphasis on graphics, the campaign was not needed, used to market ea's own version of cloud drm, not a true Battlefield, tries to be call of duty with all those cqb maps, factions were made irrelevant by giving them the same weapons
BF 4 - No mod support, no co-op, glitchy release, campaign sucked and was not needed, basically BF3, not a true battlefield, tries to be cod, factions: see above