I like the new R6: Siege. Its just a 5vs5, so nothing too chaotic, and compared to, for example Counter-Strike, it is much more slower paced and tactical.
Of course good aiming can save you in a lot of situations but with a good pair of ears and a thinking brain you can gain an advantage too.
As I am an older guy, I prefer this more tactical type of shooter over the others. I only play the PUBG with friends, not really my type of game otherwise, and Overwatch is too fast paced for me, that I play really rarely.
But of course R6: Siege is much more faster paced than the first Rainbow Sixes that came out back in the day, I have not played Vegas but the first one and the Rogue Spear and then nothing until Siege. So don't know how it compares to Vegas but against the first two ones, sure, its faster paced, but to me not too fast.
One game I forgot to mention that I recently purchased was the Escape from Tarkov. Deep in beta still, it is a promising tactical survival FPS with complex bleeding mechanics and generally a VERY, VERY SLOW PACED gameplay. Old me likes.