Freekick, Def Wall and Heading specialist.
These are the 3 SA's I find to be useful in the game.
See them activated usually and help in scoring and saving goals.

Not saying that you wont score any FK goals without SA, just that FK SA helps those without that inert talent (randomly given by Nordeus) to score more than they would.
Same goes for Def Wall and Heading.

Playmaker, dribbler, the GK SAs, etc, these ones....I rarely see them activated