The Four Points in Cologne is a very nice hotel (the exterior does not look as nice as the hotel is) near Cologne Railway Station. The bathrooms are very small, but the rooms are nice, though not always big. If you are Plat. you will get a Suite, if you are only Gold it depends a little bit of the time of your check-In.

I have put a report of my stays and some pictures on my homepage.
which may be helpful.

The hotel offers a T-mobile W-Lan Hot Sport, but ask for a room where it is available. I have had some troubles in the past.