Hey Chris,
you are 6 weeks in Hannover, then I would say you can go to:
- Hansa Park (Nessie, Crazy Mine)
- Heide Park (Limit, Colossos, Big Loop)
- Movie Park Germany (FX, Bandit, Ice Age)
- Phantasialand (Black Mamba, The Michael Jackson Ride) LOL
- Autostadt (Wolfsburg, near Hannover)
- FORT FUN Abenteuerland
- Toverland ???
- Walibi World ???
Do you have a car there? I mean, when you have 6 weeks, you can go to more parks, like Europa Park and Holiday Park!?
If you need more infos, feel free to send me a PM.
--Sören