I love rjdriver's crosshair, it's pretty well-visible and precisely positioned :)
Within the brackets a little to the left from the crosshair's central dot you can see a manhack (and another one just behind the left bracket), it burst into sparks and fell down the next moment ;)
With this crosshair you can snipe down manhacks and scanners even if they are against a brightly lit wall and at a great distance.
Installation is explained in the previous screenshot's description ;)
View this in HD to see the crosshair and the target well :)