The first one’s by Steele Savage — I’m guessing that’s a pseudonym.
Next we have Powers, as usual for these posts of mine.
Uncredited but fairly creepy cover art.
Switching to comics, we have one of Steranko’s pop-art pieces for Nick Fury, Agent of SHIELD.
And one by Jack Gaughan
And another uncredited cover.
All rights to all covers remain with current holders.