It depends if the Hollows did good deeds or committed crimes during their time as humans. There are hollows who were pluses, such as the Hollow Acidwire, the spirit of Orihime's brother Sora, was a good person before dying. He shattered his mask completely (which did not turn into an Arrancar in the process) but remained with his hollow body and purified himself with Ichigo's Zanpakuō to Soul Society. And there are hollows who committed crimes before their death (as humans) such as Shrieker, who was sent to hell instead of to Soul Society as a result of committing crimes as a human.that depends on how they die. If they are slain by a zanpakuto they go to either the soul society or hell depending on the deeds they did before they die. If they are killed by a quincy they just die.