I don't disagree with the 3 strikes law, because for every crime they have committed, there are probably dozens of others where they haven't been caught.
However, I think the law should be only for crimes against others where injury, or potential injury, is caused (armed robbery is an example of a potential injury; repeat DWI is another). Stealing pizza would not count, unless a weapon was involved.
That said, I would make punishment for non-violent crimes a lot more painful: full restitution plus significant penalties. And, if the criminal doesn't pay, then his assets and those of his family can be sold. So, if you want to steal a piece of pizza, go ahead - but you will lose your house and your car. See if that pizza is still as attractive if you end up making your aging mother homeless. (note: Israel used to do this in Palestine - young men knew that if they wanted to martyr themselves, that's just fine but, after they were dead, their families were destitute because the Israelis bulldozed their houses).