You can live without a functional liver, but then you have to go through dialysis. And you can live even if you have an entire lung removed. The spleen can be removed if it's damaged and you'd still live. However, people without a spleen are more prone to infections.
Also, women can have their uterus removed in a hysterectomy as a treatment for cancer, or other reasons.
But of course, you'd need your heart, brain, at least one lung and one kidney to survive.