i lived in leipzig for 5 years and i really enjoined it. the old town is absolut fantastic. small lanes, a lot of shops, old buildings and unlike berlin for instance, leipzig have only one city center. in the city center there are many shopping facilities and a lot of clubs to dance.
you should´n miss to visit the "moritzbastei" close to "augustusplatz" with its opera and so called "leipziger gewandhaus".
leipzig had so much flair and i´m really sorry that i had to leave.
if you´ll visiting the city of friendly people too, you would be loving leipzig like i do. don´t miss to perambulate the "völkerschlachtdenkmal". a high historical monument with a beautiful view over the town.