selective sinning

As Christian which of the 5 below would we consider to be the worst sin?

1. stealing a sweet
2. stealing a purse from an O.A.P
3. having a gay relationship
4. breaking into a house
5. murdering someone

As human beings we may consider murder as the worst but in the eyes of God sin is sin but even as Christians we seem to look on some sins as not as bad as other sins. Do we HATE sin in the same way that God does or do we pick and choose which sins we wish to target more than the others?

I had a conversation with my girlfriends 14 year old daughter and we started looking at sin. At first glance the idea of murder was worse than stealing a sweet because it had a direct effect on the person and their family but stealing a 60 pence mars bar had no real effect on anyone.
We also looked at someone having a gay relationship and that can be said has no effect on anyone as well. We came round to the idea that it could effect the parents etc as they have lost the chance of grandchildren but for all intents and purposes it has no major effect.
The real question on her mind was why are we selective when it comes to sin?

As Christians we tend to say "I believe it is a sin because the Bible says it is" and sometimes we do tend to compromise and say "well stealing the sweet is not as bad but its still a sin"

If we are ready to HATE SIN in the same way as God does, then can we really pick and choose which sin we are comfortable with?