Other than some of the large cities in Belgium what other towns would be great to visit? Traveling from Amsterdam to Luxembourg.

By car or mass transit (and for that, train only or are you willing to do a train+bus combo). How much time do you have? What are your interests?

I liked Bruges, Ghent, Antwerp, Louvain, and Ypres. Also Brugge, Gent, Anvers, Leuven, Ieper.

I wasn't much taken with Popperinge.

Travelling to Luxembourg will take you through the Ardennes. A really beautiful hilly area. You can visit Spa, home of the water. You used to be able to drive over part of the Fromula one course at Spa-Francorchamps, but I'm not sure that is still allowed.
There are many lovely small towns, little rivers etc. To really appreciate the area you do need a car.
Bruges, Gent, Ypres etc are too far north for a logical trip - go through Maastricht, also well worth a visit, as is most of south Limburg. Don't ry it on a summer Saturday though - it is the main route to the south of France from Holland/Belgium and gets seriously crowded.
If you need to hire a car then I suggest you get the train to Maastricht and hire one there - the A2 is one big mess of roadworks at the moment.

Ostend (Oostende) has always been my favourite Belgian city since I went there as a kid. It's a seaside town.

Well, I'd have a hard time planning a trip to Belgium and not visiting Brugge and maybe Gent. Yes, they're a little out of the way from your direct itinerary, but Belgium isn't large and Brugge is only 45 min via train from Brussels. It's a captivating city. Very, very worth a visit.

I love Bruges, one of my alltime favorite stops. I stayed at the Hotel Adornes and it was perfect.

If you're in the Ardennes, what about Namur?

But as I said, if you want oend up in Luxembourg it makes no sense to go to Brugge or Oosteind, completely the wrong direction. The Ardenne offers mor than enough lovely towns and village to be getting on with. They are French speaking btw.
BAstogne province was the site of the battle of the Ardennes, and on the edge of the town is a memorial to the US fallen. La roche is interesting, there are so many nice places in that whole area.

"BAstogne province was the site of the battle of the Ardennes".

You meant the Battle of the Bulge. It should be a must see. It's one of the main reasons we speak English rather than German.

Curious

Curious, the Battle of Ardennes was a major defeat for the French at the start of WWI(AKA The Great War).

depending on the time you have, try to see brugges (3 days/2 nights if possible) and take a trip to the village of Ypres. I took a full day tour from Brugges to Ypres with quasimodo tours - excellent, knowledgeable guides. their passion is WW1 and the Western Front and it shows.

The Battle of the Ardennes was in 1944-1945 and was an important defeat of the Germans by the allies. It cost many US soldiers their lives however. I don't know if it has another name in ENglish - in Dutch it is de slag van de Ardennen, hence my translating at as Battle of the Ardennes.

Just Wiki'd it and see it is the battle of the Bulge. Sorry for that - comes of looking things up in Dutch.

And really do stop suggestion Brugge and Ypres - they are way out of the way for a route from Amsterdam to Luxembourg - look at a map!

jsmith,

The French have lost just about every battle they were ever in. The Germans are another story. I think the Bastogne area is more familiar with the Battle of the Bulge.

Curious

Brugge gets my vote