This page is a list of all the science fiction and fantasy series that I rated at least one heart, i.e., all the shows I love. I'll be listing them in order of most loved to least loved, but they're all top tier shows, IMO. (Please note I'm not 100% sure of the actual order these should be in. It's hard to remember/judge.)

Star Trek: Deep Space Nine (4 hearts)
Star Trek (4 hearts)
Star Trek: The Next Generation (4 hearts)
Babylon 5 (4 hearts)
Firefly (4 hearts)
Doctor Who (3 hearts; classic series)
Doctor Who 2½ hearts; modern series, average between doctors. Highest rating 3 hearts)
Farscape (3 hearts)
The Hitchhiker's Guide to the Galaxy (3 hearts)
Quantum Leap (2 hearts)
Red Dwarf (2 hearts)
His Dark Materials (1½ hearts)
Smallville (1 heart)
Honey, I Shrunk the Kids: the TV Show (1 heart)