I can recommend Frohburg in September. They shut the Chemnitz to Leipzig road for 2 days, the grandstands are artic trailers and the track is mental. If you go there any other time you might wonder what the 'laybye' on the left is - it's the chicane to slow the bikes down as they go down the hill before the right angle left hander which has straw bales against the house on the inside of the bend and the main road has the start line across it all year round!!! The last race on Sunday is the Joey Dunlop Classic. One of my friends lives in Frohburg and used to go and watch MZs screaming round this track before the wall came down, 3 years ago Rico Penzkoffer took a works BM Superbike round.
http://www.frohburger-dreieck.de/