Home security, like handguns, seems to always be a compromise between what's most effective, and what's most efficient. I think those who rent, or who intend to move within 10 years, probably have it pretty rough when settling on security ideas.
If you own your home and intend to live and die there, you're free to make it a residential fortress, as a poster above mentioned. We've gone pretty extensive around here as I've mentioned before, you're not getting into my house without machinery. However it took money, and it took time, and if I were ever to sell this joint those measures have about zero recoverable value. Odds are high that the next buyer doesn't give a rip that the glass slider is bullet resistant, or that you'd have better luck coming through the wall than the front door.
If you're not in a position to go all out tin-foil crazy with it, plenty of the off the shelf products mentioned in this thread will certainly slow someone down enough to buy you a little response time.
Then once you buy the house you intend to keep, send the missus on a nice vacation, remove all the drywall, and start ordering up the steel. Heh.