there are a lot of factors that need to be considered, sun or shade, foot traffic, water requirements, how often do you want to mow, etc. one of my favorite grasses for look and performance is Tif Sport 419. This is the grass that A&M uses on it's sports fields. It is finer textured than St. Augustine, requires less water, more mowing, and it requires full sun. It has better foot traffic durability. I have attatched a link so that you can sort through some of the other grasses and make a more informed decisions.
http://aggie-turf.tamu.edu/answers4you/selection.htm