For me, seeing the Remagen Museum would be number one. A long time friend (age 90) and my uncle, also 90, landed on the Omaha beaches and both in different units, were in Engineering. Our friend was in the unit to tear down the Remagen and rebuild it in two weeks. Every torn down piece had to be hauled away by Army trucks, and every rebuild piece had to be hauled in also by trucks--so my friend told me.. They worked 24 hours a day till done. When we were on the Rhine and Mosel river cruise in 2007 (I think), we passed under the new bridge and saw the biggest and most beautiful American flag at that point flying 24/7--a memorial of America 's part in rebuilding. We passed around 9:00 PM and our captain went very slow so we could see and take pictures. However it was raining, so not so good pictures from inside. We did not get to go to the Museum, so can't comment on it. This place is a very important historical aspect to the beginning of the end of WWII. The only place that I know of outside of an embassy, consulate, or military base in Germany that the US flag flies 24/7.
Having said that,weI've been to the Battle of the Bulge three or four times, and find it almost as moving. The first time in 1962, we couldn't drive all the way up, so the local shop keepers told us to park on the dirt road and they would watch our car. They all came from their shops, running up to my husband, with his Army haircut, they knew we were Americans, and thanked him for saving them. My husband at that time was just a 20 something, so he wasn't there during the battle. And to Luxembourg several times as well, once for several days, also on the first trip to Battle of the Bulge. Our last trip to this area was in 1975 and the road was paved, several lanes, and the monument finished. It is a sight to stand at the monument, glance all around in the distance, to imagine the Americans and other countries' soldiers advancing through those hillsides to gain momentum for what was to come. Both are interesting to see and historical.