What's the most useful linux distribution?

I have a knoppix linux 5.1.1 DVD boot live CD a complete OS in DVD just boot it and use it, no installation, devices are all auto configured, a good tool too to recover data on a failed window. It has an open office, graphic editor, browser, disk tools even game. I'm amaze on how they did it. If I would have the time and space, I'll definitely install this one.

ubuntu is easy to use gentoo is highly configurable fedora is usefull, many programs knoppix is fast puppy linux is the fastest ... you choose what you want

I do not use Linux. I have played with it a little. Now probably the best is Red Hat Distribution. as most distributions are a derivative of the Red Hat Version.

what you have learnt about linux is true. You dont need to pay for the linux. You can download it from the websites of the manufaturer. Some of the famous Linus operating systems i have used are Ubuntu linux, Open Solaris from Sun Microsystems, Fedora from RedHat and there are others too. All these you can order a free DVDif you dont have a good internet connection. In that case Ubuntu DVD you can get very fast goto canonical.com for ordering it. Then sunmicrosystem's Solaris is also free(i heard recently they went for commercial, just check before it). Its good in the sense it comes with many Devepoement tools and IDE's preinstalled. Then Fedor, they say they have free distribution but form last 3 months it is always already done, so you have to download it no other go. then you can try for other also.Then you also try the option of openSUSE, it claims to be good for new users.

i think fedoro is the best as it has all the features and also it is free