I would suggest a KEYPAD and have a locksmith disable the "backup key".
A door bell, and a entrance camera so you can see who is at the door.
Remember, insurance companies deny claims if there's no proof of forced entry!!
1) Go to a locksmith store, find the Schlage B60 or equivalent, usually $30-$50. Have the pins inside replaced with Mushroom Pins, which will prevent 'bumping'. Basically mushroom pins have a mushroom top, when bumped fall to the side grabbing it, and defeating the bump. Then have it re-pinned for a deeper, more complex keyset, the deeper/complex the pin layout, the harder to pick/bump. (6,4,9,5,7,9 or something) These come with anti-drilling protections, pick shields, and will suffice for the majority of cases. I know expert locksmiths that spend days and days in the shop trying to get through these. They aren't impossible to get into, but offer some pretty significant protection at a low price. OR buy them, then take them into the locksmith store, have ALL mushroom pins installed, and rekeyed to be higher security.
2) Purchase Medeco locks, or a similar high security brand. These are fairly secure, although not impossible to break, and nobody can just go get a key made. They come with a credit card that has to be used at a locksmith to 'authorize' a rekey job. But these cost $120-$300 depending on model. Also, when an agent, crook, or anyone else sees Medeco on the door, they think "This dude knows about security..", it's an alarm bell for them, they get scared, they don't know what ELSE you might have..
3) Purchase Schlage Everest locks off Ebay. Only pro locksmiths can make keys for these, and they are extremely hard to break into. They do not make them anymore, so any you find will be ones before production was stopped. They have side pins that prevent most picking, and prevent bumpjobs. Cost is quite low, about $50-$70 each on Ebay.
Remember, you can buy bumpkeys for 90% of all locks for $8.00 for a complete set on the internet. This ensures 1-5 second entry to virtually all homes.
DO NOT ASK ME HOW I KNOW! 