I stayed at the Royal Hotel Versailles for 3 nights. The staff were very helpful and spoke good English. The breakfast is optional; it's a pretty big meal if you take everything they offer. The location is about a 10-15 minute walk from the main entrance of the Chateau. Along the street are a couple of banks, clothing stores (I bought a nice summer dress for 35 Euros), restaurants, and a pharmacy.
My room was quite spacious for a single, and it included a kitchenette. Like most hotels these days, they only do housekeeping every 3rd day, but when I asked at the desk for a refill of Kleenex they immediately replenished the tissue holder in the room rather than expecting me to take the new tissues to my room myself.
It has an elevator. It doesn't have air conditioning (except in the basement breakfast room), but my room came equipped with a good quality oscillating fan. The windows had blackout drapes, which prevented the room from getting excessively hot from the sun.
I thought the Royal Hotel was a good value. I would happily stay there again.