Mac the Ripper will take a DVD and desposit it (without Macrovision, I believe) where you choose on your hard drive. You can choose movie only or the whole things with menus. Filesize will be pretty much the same as the DVD (4-8gb)
Handbrake will rip a DVD into a compressed file.
If you want to preserve 5.1 sound, I would rip to DivX and play in VLC Player.
If you want to play in Frontrow, I would rip to mp4. Use H264 for smaller filesize. However, you will only get stereo though quiktime (which Front row uses)