My favorite multi has to be the Babolat xcel string(16 gauge). This is the most popular choice of string for the customers I string for and I get nothing but great feed back. I also tested out this string @60 pounds and was very pleased.
Even at 60 pounds this string still was very soft and offered arm friendly play. This string had tremendous feel and played with great control. As I continued to play throughout the week these strings held there tension and continued to play great. I played for 2 hours with this string each day and by the end of the 2nd week they began to fray and that allowed amazing spin control. 3 days into the 3rd week they broke but I hit with a lot of spin and break strings very often and these held up longer then other multis I have played with. Although they are a bit expensive they played the softest had the most feel and control throughout the strings life.
Ultimate Federer fan, Tennis Guru, Wilson blx surge, Luxilon 4g @55 pounds