You didn't give much to work with but I like KNOPPIX since you don't have to install it to see if you can use it. SUSE and others have LIVE CDs you can test drive until you find what you are looking for.
I want to switch my windows computer to Linux but have no idea where to even begin. I'm not a computer newb, but I am new to Linux. The machine I want to install it on is a pentium 4 3.06ghz with over a gig of ram. I'm not even sure what other info you'd need to help lol. Perhaps someone could suggest the right form of linux?