...I continued to think of people that I've been over joyed to hear they've gone!
Will be different for everyone.
Examples for me, terrorists, bullies, some really nasty people I've known over the years, the guy who raped my friends daughter (who died in mysterious circumstances ) and many others.
So my point is, is it ok to be happy that certain people die or am I wrong to feel that kind of joy?
For me, there is a subtle difference between wanting someone to die, and wishing they were not alive or wanting them off the planet.
It is subtle but one of the big differences is my own attitude. Do I want revenge, or do I want cleansing?
Revenge, like hatred, is damaging to both individual and society. Cleansing—wanting a society without such people in it—offers the chance for rehabilitation of those people (cleansing by changing) and avoids the trap of their evil (if that is what they have) infecting me.
So long as your hatred is not overpowering, there can be a certain gladness that someone is no longer among us. Only an overpowering hatred will not be satisfied even when someone is dead. Overall, the number of nice people vastly outweighs the number of nasty ones, so we should mostly feel for all those who die needlessly, and feel for those they leave behind.