Renaissance La Défense, weekend-rate apr-7 to 9-2000: 750 FFr/night (without breakfast, booked on-line (the rack-rate published in the room is Ffr 1'950 - I hope nobody will ever have to pay so much).
La Défense is one (RER = express-métro) station from l'Arc de Triomphe (tombe of the unknown soldier). Last train back at about half an hour past midnight, afterwards a taxi costs about Ffr 120 from l'Etoile.
The Renaissance hotel is (inside) very nice, modern, efficient, with all comfort and services you expect from a ****hotel (but no Paris athmosphere) and just meters behind la Grande Arche at la Defense (sortie autoroute La Défense 7). Free coffee until 9AM weekdays, 10AM weekends.