Personally I don't think it makes one iota of a difference that you are an MD. It's not like your credit score will be weighed any differently.
That said, I have had many, many cards -- Capital 1, Bank of America (was Fleet then they got bought), Providian, Amazon.com card, Citibank (both visa and MC), Discover, Chase, GM Card... I am sure I am missing some.
I have since closed some of those accounts, but right now I am using a mix of MBNA, Citibank (both visa and MC), and Chase. MBNA is ok but their interest rates are always the highest out of all the banks in general. They are known to give insanely high limits. I have had to resolve 2 disputes with them and it was easy (albeit by mail though which is archaic nowadays).
I really like both my Citibank cards and my Chase card. Both have rewards on them. You get one point for every dollar you spend then you can turn the points in for stuff (or cash back/credit). The main reason I like citibank is bc I am a citibank banking customer so I can transfer payments easily (although you can just as easily do an EFT to any other CC as well).
I don't carry balances on any of my cards so I don't really bother with the interest rate or grace period lengths. I really just like the points thing and the ease of managing the account online (Citi is better than Chase in this regard IMO).
That's just my $.02 anyway.