There are so many choices out there but what is the best and simplest to use home camera system that allows you to monitor what's going on at home in real time and also records to your hard drive if you need? Hopefully no service charges or anything like that....
iCam
The app is $5 on the app store, desktop app is free, and it uses a webcam enabled PC/Mac as the source. Supports live video streaming to your device.
It will send you a push notification when it detects movement and will snap a picture and save to a folder, no video recording though.
With the desktop app, you can enable movement "detection zones" that are within the camera's view.