[Black Robed One]

IMHO, Baldur’s Gate II is (IMHO) better then Baldur’s Game I (I’ve played both, but I have only BG1 at the moment), as BG2 has (IMHO) a longer and more interesting storyline and some VERY interesting interactions between NPCs and between the main character and NPCs (BG1 has more recruitable NPCs, though).

However, just like many others before me, I’d advice you to start playing with BG1; if you start playing BG2, you will miss much of a storyline, and if you move to BG1 later, some important events will be spoiled for you by BG2. Moreover, when you finish with BG1 you can go ahead and import your BG1 character into BG2, as it is meant to be.