Most desired scientific discoveries on reddit, along with my own predictions on when they will be achieved (which are more pessimistic than those of the scientists working on these problems):
- Immortality [consciousness uploading; 2150]
- Alien life with which we could meaningfully communicate [millions of years if ever; too far away...]
- Cure for cancer 
- Cheap/clean/abundant renewable energy 
- Warp drive [never?]
- Affordable female android sex slaves 
Also, Vox Day has published his 6th letter to me.