In the past I've tried several, and almost all have damaged my system.
So actually I use CCleaner (only cleaner option), and rarely, only if it really can not be avoided, RegSeeker or Glary Utilities Pro.
Advanced System Care
CCleaner
Eusing Free Registry Cleaner
Glary Utilities
jv16 PowerTools
System Mechanic
TuneUp Utilities
Win Utilities
Wise Registry Cleaner
Other (please mention below)
In the past I've tried several, and almost all have damaged my system.
So actually I use CCleaner (only cleaner option), and rarely, only if it really can not be avoided, RegSeeker or Glary Utilities Pro.