I've stayed at the Grand Hotel Mercure Chateau Perrache (yes, I've stayed at all this ), and found it nothing short of fantastic. It's a magnificent building, and I somehow got upgraded to what must have been a deluxe room on a very high (if not the top) floor with a stunning view of the whole city. On a rate of €65 per night!
For random dates in June, I'm seeing €117 for the deluxe double and, if you want to splash out, €240 for the 50m2 suite!
Just don't pay the €13 (or whatever) per person for breakfast; there are numerous cafés nearby that will do excellent coffee+croissants and give you change from a €5. And be reasonable at night (don't linger around too long, take a taxi if arriving after 23:00 or so), because it's next to the train station. Wouldn't really call it a dangerous area, but you need to remain focused.