To entertain myself through the week i currently watch:
True Blood (actually just finished last week) - Southern vampire mysteries is how the books it's based on are described. Started off a bit silly, with more sex than was necessary, but entertained me for 12 eps once they got into the murders.
Created by Alan Ball, starring Anna Pacquin.
The Big Bang Theory - a comedy about geeks, i love it

Two and a Half Men.
How I Met Your Mother - only got into this recently but i'm finding it quite funny.
Heroes.
House.
Fringe - a rather good twilight zone/ x files type series. The main characters include a crazy scientist and his son (with a mysterious past of course) played by Joshua Jackson. I started watching it just cos I always loved Pacey and haven't quite gotten over it

but it's got potential to end up awesome.
Dirty Sexy Money - second series doesn't draw me in as much as the first but it's still worth a look.
Grey's Anatomy.
Supernatural - Jensen Ackles, I love you
Stargate Atlantis - yeh, so it blatantly copies half its storylines from SG-1 but it has Rodney McKay in it and he's much better than Sam Carter.
Sanctuary - the show Amanda Tapping moved to about an apparently immortal scientist who helps abnormal creatures who're nice and kills the bad ones

Legend of the Seeker - based on Terry Goodkind's Sword of Truth series, which was a bit hit and miss at the best of times and the series is coming across as Hercules/Xena without the fun side but i'm hoping it works out cos high fantasy has never really made it on TV before.
Eleventh Hour - based on the British TV show, most episodes appear to be about some silly person taking advantage of a scientific breakthrough to kill people or accidentally kill people. But it has Rufus Sewell in it and he keeps it going well enough despite the fact his character is meant to be a biophysicist but apparently writes papers about dark matter in his spare time

CSI - I prefer NY but i'm getting into the original again now they've finally gotten rid of annoying Sarah.
Law and Order - there are 18 series so if you're looking to completely fill your time there's plenty to get through - it's the default show i watch when i don't have much else to do.
And this isn't including the anime i watch when i run out of American things, or my saturday night obsession with Merlin, the X Factor and Casualty, or Mock the Week, QI, Never Mind the Buzzcocks, Have I Got News For You... - i, rather obviously, have too much time on my hands

"This is my story. It'll go the way I want, or I'll end it here"
--Final Fantasy X