My Parents and I went to Weimar in 2001 on the way to the north of Germany. Although it was quite cold because it was autumn the town was lovely to look at. The sun was shining and we could sit outside drinking coffee. The house of Goethe was very interesting to look at because seeing all those pictures furniture and also instruments he used to experiment gave a good inside in what kind of person Goethe was. He was close to being an universal human being like Leonardo DaVinci.
One very practical thing about Weimar is that it is not too big in terms of distances. You can walk just about everywhere and there are not only sights but also the lovely pedestrian zone with shops and cafes.
Unfortunately we only had a few hours there but I am really looking forward to visiting Weimar again but this time it will be right in the focus of my trip.