I did Hotel Grand Leveque, and would stay there again without hesitation. Modest, but quiet, clean, safe, and great location. A block off the subway, maybe six blocks from the Eiffel tower one way, maybe eight to the Arche de Triumphe the other. It's on a market street, which means primarily foot traffic. I stayed a couple of years ago for about $45 US, including breakfast. They're showing 53 euros for a single with shared bath now. Here's the web site:

http://www.hotel-leveque.com/

JP