Premex, the Orly HILTON is a terrible thing to do to you trip to Paris. Inconvenient, far from everything- except the Orly airport.
I'm French, listen to me :

Get a hotel in town. The Libertel chain, which unfortunately just terminated its agreement with mileage plus ( THAT was a great way to use those hotel coupons!!!!!) ;-( is always a decent bet. They have hotels everywhere in Paris, check out their web site.
I like the Grand Turenne, it's a small intimate thing, friendly staff, in the best area of Paris, le Marais. You get off the RER at Chatelet and change to Line 1, it's near the Saint-Paul station.
Buy the 80FF weekly coupon for your travels on the metro/bus, it really is the best deal.

Jet Bus is on strike.

Catch the RER from CDG to Paris. Why were you going to stay at ORLY, are you flying AF domestic?

[This message has been edited by Droneklax (edited 03-10-2000).]