Which camera type is better for digital cameras: Kodak, Casio, Nikon, Sony?

KodaCaSoNikon.

There is no "type" better than any other. They're brand names... they wouldn't have a business if no one were buying their products. Sony owners will recommend Sony, Kodak will recommend Kodak, and so on. Read some reviews, look at samples and interpret the results to find the one you like without having someone tell you what you like.

Here are a few good review sites:
http://www.dpreview.com/
http://www.dcresource.com/
http://www.steves-digicams.com/

Also consider Canon, Panasonic, Pentax, Samsung, Olympus, and Fujifilm.

Everything depends on the camera itself and not necessarily the manufacturer. Every single one of the companies listed make some top notch camera, and some real stinkers as well.

This is the equivalent of asking, who makes a better car? You can't be that general and get an answer that is absolute.

That being said, I will throw out some food for thought (and some personal conjecture)

Canon is by and away the largest camera manufactuer, out of the companies you listed, they and Nikon have the best of the top end cameras, but we are talking about $4K and up. Casio is better known for lower end camera up to about $1k, but nothing in the "pro" class. Sony has come on strong for a late entrant into the camera market, but most of their good cameras (that I have seen) are based not on their own technology, but the stuff they acquired when they bought out Konica-Minolta's camera division. Kodak, definitely brings up the rear of the group but has some decent cheap camera.

Pay more attention to the features than the brand.

There are some very expensive brands that don't hold up as well as the cheaper ones when it comes to features. They will all last about as long with proper care, but, I would stay away from Cannon, I've heard a lot of problems with them.

Look for a Vivitar Vivicam. I just got one for under $100 and it has photo, video, 7 MP, built in rechargeable battery and comes with a small amount of built in memory. The same features in a Cannon or Sony are well over $200.

They are all great .. I've got a SONY and NIKON .. love them all

Better question/issue.. make sure you have enough MP and try out the settings on the back to make sure it makes sense to you ...

none, canon all the way, they are affordable, attractive, and have great photo quality.

sony

Well, I'm really a Canon person... but of these four, I choose Nikon.