We don't have cable, but I watch some television shows on Hulu, etc.
Right now my favorites include Eureka and Warehouse 13. The scientific underpinnings are laughable, but the shows are fun! A new show on the SyFy (really, what was wrong with SciFi???) network called Haven looks fun -- it seems to be loosely based on Steven King's The Colorado Kid. Basically, these are science fiction shows with a second focus on comedy, relationships, etc. Not very deep. but fun -- and at the end of the week, there's nothing wrong with fun!