Whichever one grows best in your area! They all taste the same.

On the same lines, just noticed white sappy foam all over my Rosemary. It's been 110degrees this week and it was dry. What is that stuff?

sounds like spittle-bug but I don't know if that'll attack rosemary.

The least appropriate variety would be trailing rosemary - it doesn't have as much of the flavor as upright rosemaries do. Keep in mind that rosemary will grow into an enormous shrub unless you keep cutting it back. I usually replace mine every 6 or 7 years because I will forget to cut it back over the winter and it turns into a monster! Try to find a variety with dark purple flowers - when they flower they are stunning!

Tuscan Blue is supposed to be the one chefs use. My Rosmary plants are covered with spittle bugs. I hose them off, but they don't seem to do much harm as the plant can grow faster than they can eat it.