There are many brands of cream out there, but I recommend the lines from Jerome Russell, Fudge, Manic Panic and Clairol. Jerome Russell manufactures Punky Professional , which is probably the best line of hair dye you can get your meat hooks on. The colors are really bright, and they tend to last longer than the other brands. They're also easier to find than any other line on the market. From Fudge comes Paintbox , which is the easiest to apply and least messy.
Paintbox comes in a tube, making cleanup relatively simple.
This brand also comes in sixteen colors, five more than Punky Professional. If it's variety you're looking for, then Manic Panic is for you. Manic Panic is very messy. It's extremely watery, and if it spills, it's certain death from your mother. If you're looking for products easy to find and use, there's XtremeFX by Clairol.