Might be a little long (ICE Trains take 38 mins) A route where ICE trains fly by at 145 mph with little stopping trains and S-Bahn as well. Stops: Hannover Hbf, Hannover-Kleefeld (S-Bahn), Hannover-Karl-Wiechert-Allee (S-Bahn), Hannover Anderten-Misburg (S-Bahn), Ahlten (S-Bahn), Lehrte, Immensen-Arpke, Dollbergen, Dedenhausen, Meinersen, Leiferde (b Gifhorn), Gifhorn, Callerbah, Wolfsburg-Fallersleben and Wolfsburg Hbf Trains: ICE1, ICE3, big purple trains (don't know train fleet but i know they are big and purple), DBAG Class 424.
I really want to see Hamburg to Hanover brought over from TS to TSW - it's a great route! Not just for ICE but there's plenty of route for the BR 101 to get a good long run too