Darkseid is a major nemesis of Superman (as well as the rest of most of the DC Universe) and leader of the planet Apokolips.
His first comic book appearance was in 1970 in Superman's Pal Jimmy Olsen #134. He was created by Jack Kirby.
His powers include:
The Omega Effect - concussive and/or disintegrating energy beams (also allows him to teleport through time and space)
Superhuman strength, stamina, speed, agility and reflexes
Silver Surfer, formerly Norrin Radd, was an astronomer on the planet Zenn-La that offered his services to Galactus in exchange for the life of his planet.
His first comic book appearance was in March 1966 in Fantastic Four #48. He was created by Stan Lee and Jack Kirby.
Silver Surfer possesses the Power Cosmic which gives him the following powers:
superhuman strength, stamina, durability, and senses
he can travel through space on his cosmic surfboard as fast as the speed of light
limited telepathic ability
the ability to heal living organisms
energy projection for offensive and defensive purposes (it has been said that his cosmic bolts can destroy planets)