As I live on my own in a rented property, I had to get creative. I do love my gadgets so I have a combination of products.
I use Samsung Smartthings home automation, sensors and monitors are all wireless. Combination of motion sensors and contact/vibration sensors you can use on doors and windows. You can also get moisture and presence sensors.
I then have Philips Hue wireless LED bulbs. I also have Netgear Arlo wireless security camera, which is full colour and also IR at night. These have benefit of being able to be used outdoors also.
These are all connected through the Smartthings app. If I'm not at home and someone's fiddling with my window, lights will come on. (also great for if on holiday as you can remotely switch lights on and off). if someone actually enters detected either through front door opening or motion sensors, the camera will start recording and alert me straight away.
I only went this way as I can't permanently install anything, but I think gives greater choice of combination of sensors as you can keep adding more if you need to.