Yep! She'd have become next Dark Lord..or.. Dark Lady.. LOL!

Bella would have gone mad without Voldy.

^ As if she wasn't mad with him.

I think so. If not she'd probably refuse to believe he's dead.

I think she would round up the death eaters to try to find a way to bring Voldemort back. She'd probably do that till her death or till she would was and put back in Azkaban (or given the Dementor's Kiss). Or if she ever did accept that Voldemort was dead, I think then she would suffer the full metal break down.

She was already mad before. Azkaban did not improve her mental state. Difficult to say. Maybe she would have collapsed for a while but Bellatrix being who she is, she would have used that collapse to bounce back and try gathering the rest of the Death-Eaters for a new crusade of her own. Who knows ? Sensible question.

no she was nothing without her obsession: Voldemort.

I don't think so. In spite of her obssesion, loyalty and fanatical devotion, she was never in charge. Before the events in DoM Lucius was the leader of DEs and Snape was closest to Voldemort until the end. I'm not saying Bella wasn't appreciated by Voldemort (he trusted her with a horcrux after all), but she wasn't his right hand exactly. That's just my opinion though.

she loyal and she be mad

She would suffer at first,but then she would wanted to continue what voldemort started and take revenge for his death!!!That would be a great sequel to the harry potter books:P i mean only voldemort to have died at the end and bellatrix to be the next villain and take the leadership of the DEs!!A new whole bunch of seven books(or less) for the series:P

I think she would refuse to believe he's dead and go on with his course or try to find him or something....and like the first time when he fell she'll be the only one fanatic enough to sacrifice everything for an absent leader