Indian Music?

Years ago I listened to Ravi Shankar occasionally and enjoyed a lot of what I heard. The other night I watched an interview Charlie Rose had with a very famous tabla player and his music was superb. I'm thinking that I should explore traditional Indian music a bit further but have little knowledge of the subject. Any suggestions on 2-6 CDs I should check out for starters? I prefer instrumental but would consider vocal as well. Thanks!
PS: If you're suggesting obscure titles, sources would also be appreciated.