I learned to read with scifi. "See Dick, See Jane" just wasn't cutting it, so my mom taught me to read with Skylark of Valeron, of all things. So, yeah, I still like E E "Doc" Smith after all these years, both Skylark and Lensmen series. In fact, I like all the old pulp scifi I can get hold of.
Let's see, what else?
Lovecraft basically set my standards for horror. You can have your zombies and vampires (but Lumley did what I thought was a nice Lovecraftian vampire series), I'll take the multi-tentacular extra-dimensional horrors every time.
I also like military scifi and fantasy: David Drake is a big one for me. Hammer's Slammers, Northworld, pretty much anything he's ever written. Elizabeth Moon (IIRC) has a good military fantasy series with Paksenarion.
My two favorite epic military fantasy series are Glen Cook's Black Company and Steven Erickson's Malazan Book of the Fallen. I started listening to the Malazan audiobooks in late March, as I recall, and just finished them on the 3rd of July. I listen while I drive, and I usually get at least 40 hours of drive time a week.
There's so much good scifi out there, I can't list it all.
And by the way, I know the "correct" term is science fiction, not scifi, but as far as I'm concerned, that's pointless snobbery.