My first Jdrama was Hanazakari no kimitachi e back in 2007, it's still in my Top 10.
Biblia Koshodou no Jiken Techou. I know it's a weird one to start with, but I like books, so I was interested in it..
Hanazakariri No Kimitachi e (Hana Kimi-2007 version) then followed by Hana Yori Dango :)
Feeling a little old here as my first jdrama was long vacation by kimutaku....(^_^)V
Densha Otoko "The Train Man", great series but those 2 special episodes at the end weren't necessary.
1 Litre of Tears or Good Morning Call
Mine was yakizawa kiss.. I don't really remember.. It's fun, a stupid girl fell in love with a handsome smart boy
Majo no jouken  :-D some years ago
Good Morning Call and I hated it. :D

Love Shuffle and then Siren (especially Siren!!!) saved my opinion on j-dramas. :'D