Well, it is a relatively small city and in two days you have seen most of it. If I were nasty I would say the best of Leipzig are the trains to Dresden and Berlin. But I am not nasty today. It is a pleasant town but do not expect too much. Culture is great, museums are good and evenings outings can be fun. But it is definitly neither London nor Berlin.
And do not expect too much from the food. The "Sauerbraten" is a poor copy of what is known from the Rhine and there is some cynic around about Leipzig coffee described as "Blümchencoffee" (flowers coffee). This, because in the old days you could see the decor at the bottom of the cup even trough the abviously thin coffee.
Nonetheless, it is for sure the second best big city in Saxnony (second only to Dresden), but to be honest: There are no other big cities around.