I know there is quite a lot of mods out there already and I can't help but think that I've missed out on some.
I think it would be a good idea if people posted the mods they use along with a brief description on WHY they use them.
To begin I use the following:
VopSound_2.1: It offers better sound than what come with the game
SLX: MOD that makes the AI better (in my opinion) and adds a whole load of other features
Saku Lighting MODS: First mod makes the sun less blinding, the second affects lighting in the game
LittleBirds: Adds the chopper of the same name to the game
CAA1: Can play Arma 1 maps on Arma 2 (highly recommended)
CBA: Framework and standardistion for mods
I also use the Helicopter sound mod, Tracked Vehicle sound mods and the Spanish Weapons mods but I can't remember their names.
Not sure if there's an existing thread on this already, so apologies in advance.