zoom - What features really matter in a point and shoot camera?

I am planning to buy my first new digital camera. Now I am too confused for more than 20 days about how I can choose a camera.

I want to use the camera for domestic purpose.

The Canon IXUS 220 HS looks good but it is only 12 MP and only 5X zoom. But there is a also the Canon A3300 that is 16 MP.

So I don't know what is the basis of selecting a camera. What is Image Stabilization? When should I buy a CMOS sensor camera? How much Optical Zoom is sufficient? How much does noise matter in the camera?What about if the camera has HD video recording, and if not, how much will that lack affect viewing on my 32 inch TV?

The cameras I'm currently looking at are Nikon s3100, Canon IXUS 220 HS, Canon IXUS 110 HS, Canon A3300, and Sony W370/B. This will be my first camera and I can't take any risk because I cannot afford a new one in the next few years.

Answer

I would put the number of megapixels at the bottom of the priority list. Megapixels matter, but once you get past about 10 you'll have enough for anything you're likely to do. In particular there wont be a noticeable difference between 12 and 16, theoretically you'll be able to print a 16MP image 15% larger, but that's only if the lens resolves more detail and that detail is not lost to noise.

Image stabilzation prevents blur due to camera shake when you take a photo. It becomes very important the longer the zoom lens. With a 5x it's probably not important but once you get 10x or more you should definitely look for a stabilized model. How long a zoom you need is really up to you.

All small sensor point and shoot cameras will produce noisy images in low light, it's just something you need to be aware of and plan your shooting accordingly.

HD video is a useful feature, I've seen some really good quality clips from this sort of camera, so if you plan to take videos at all I'd look at one that records HD.