Well, personally I'm not always looking for a serie to be smart.
I'm searching for something to distract myself from everything..... so well after House and Lost I watch(ed)
1. Rome (great serie, especially if you have a bit of an interest for ancient history)
2. The Tudors
3. Six Feet Under
4. Desperate Housewives (I find it so so funny... I don't know if it was intented but I think it's a great eeeuh... "caricature" of the society )
5. The L word
6. Gilmore Girls (because it's so so fluffy, and that I would have killed to have a mom like that)
7. The Vampire Diaries (it's a really really realy light serie, but... baaah it's fun to watch when you're studying)
8. Gossip Girl
9. Dirty Sexy Money (first season's cool, the rest is a little crappy)
I used to watch a lot of detectivie series with mom
9. CSI NY
10. Criminal Minds
11. CSI (the original)
12. Law and Order
13. Monk (it's so so so funny)
If Cartoons count I am deffinitely recommending the Simpsons, South Park, American Dad, and the Cleveland Show (ps: i don't like Family guy)
And well there are a lot of other series I watched I guess:
Dirt, The Knights of prosperity, CSI Miami, Eli Stone, and well others that I can't even remember the name
Yes I'm a series whore