Who has the best plasma monitor these days

Panasonic is always a good bet. Some models by others are as good.

Why plasma? LCD is much improved, and if I were buying today I would probably go LCD.

With the most recent models, LCD's have improved a great deal. Before you write them off be sure you are looking at a current model. On recent simultaneous demo alongside plasmas the LCDs look better to me. (I have a plasma, which at the time I bought it was better than LCD).

For fast motion (sports) plasma is still best. On the other hand, the LCD screen does not show reflections from room lamps or windows. Pick your poison.