Many companies sell vandal resistant domes with security screws so the cams cannot be accessed easily, to protect the wiring they have conduit holes on the side and bottom of the units.
Budget is also a concern of course vandal resistant domes can be pricey but I find they look better than standard camera housings on most homes..depending on what you wanna spend you have many options.
Personally I like Axis network cameras such as the 225FD but they are pricey at $800-$1100 depending where you get them, I'm sure companies like Pelco may have similar models in wired or network versions.
You can always buy domes/housings that will fit most cameras you may already own but be aware also that special models with *heaters* may be needed in climates with very cold weather..usually they have a small heater and and fan built in powered by 24 vac.
Here is an example of camera housings for any cameras that have a hole on the bottom conduit can be run to
http://cgi.ebay.com/4pcs-New-Outdoor-Housi...82687QQihZ012QQ
**As you can see they are pretty big and may not look the best on most homes..might look like the neighborhood prison
Here are some examples of cheaper vandal resistant domes with cameras in them
http://search.ebay.com/search/search.dll?s...ge=search&fgtp=
**Basically what it comes down to is what you wanna spend and the quality you are looking for, if money isn't an object I would visit www.axis.com and check out their products...many of them can be found on ebay at good prices.