I tended to prefer space opera to "hard" sci-fi, though it depended on the writer.  I used to have an edition of Edmond Hamilton's Starwolf books; but, never got around to reading it (basis for the Fugitive Alien tv series, of MST3k fame, with the aliens with the weird wigs under their helmets).  I liked EE Smith's Lensman stuff, though his prose style was a little archaic.  Burroughs moves you right along and creates images in your mind.  Bester was one I enjoyed, with The Stars My destination and The Demolished Man, and Bradbury has always been a favorite.  Asimov I liked better on the short stories than the novels, of what I've read(which isn't a great deal of his).  Heinlein was good, though the later stuff is more hit and miss, with me.  I also tended to like the military sci-fi, from real veterans, especially Joe Haldeman and The Forever War.  Starship Troopers is rather fascist; but, exciting.  Haldeman makes for a great counterpoint to the ideology in Troopers.  I liked David Drake's Hammer's Slammers stuff (another Vietnam vet).   Harry Harrison's Stainless Steel Rat was a series I enjoyed.  Phillip K Dick is good for the philosophical stuff.  Never got into Niven or Pournelle, haven't read Van Voght or Cordwainer Smith.  I have been poking around at some of the planetary romance writers, thanks to characters used in the Tales of the Shadowmen anthologies, especially Leigh Brackett's stuff and Edmond Hamilton's Captain Future stuff.  Also like to check out CL Moore's Northwest Smith, which was one of the inspirations for Han Solo.

For comics, it really depends on the story and the visuals.  The Adam Strange stories were always clever and visually inventive and dynamic.  Captain Comet had some clever tales and the EC stuff was usually good.  Elaine Lee and Mike Kaluta's Starstruck was really interesting stuff, with great visuals and great characters.  Starslayer was a nice mix of a fantasy hero and a space opera setting.  Time Warp had some nice stories, in its brief life, especially those from Kaluta.  He also did one or two of the World of Krypton stories, in the early 70s Superman comics (circa the sand doppelganger storyline) that were really interesting, visually, as well as from a plot standpoint.  Kaluta also illustrated an edition of Thea Von Harbor's Metropolis novel (though I'm not sure if he was adapting the novel or the film script), for Donning/Starblaze.  I loved the Archie Goodwin Star Wars stories, over any other writer involved in media adaptations or the films.


For comic strips, it was always Flash Gordon, which is really fantasy/planetary romance.  Buck Rogers always sounded cool; but, the art on the strip always looked so dated and flat, until some of the later guys (like Murphy Anderson).


For Europe, there is Leo's Aldebaran cycle, Moebius's work, Juan Giminez' stuff, Daniel Torres' Rocco Vargas (mix of detective and sci-fi), Maroto's Cinco Por Infinito, Druillet's wild and weird Lone Sloane, Mezieres and Christin's Valerian, the uk strip Jeff Hawke, Dan Dare, and Pepe Moreno's dystopian albums Rebel and Generation Zero.