Can you suggest me some good (and easy) television series?

30 rock is a good one. Modern Family, The Middle, and Cougar Town are also easy. (But Cougar Town also has ual terms, so depending on your age, that might not be a good one.) If you are into comedy, Saturday Night Live is easy and my fiancee learned English using that one. There is also some talk shows that could improve your English. Like Late Night with Jimmy Fallon, The Tonight Show with Jay Leno, Last Call with Carson Daly, Jimmy Kimmel Live!, Conan, and Ellen. All those shows helped my fiancee learn English because he was born in Mexico.