dot.tk works well for me. I haven't got to the fancy stage yet of wanting to look extra good. I think when one does get professional, .com is the best, followed by .net, .org. I also like the country abbreviations like .co.uk. I probably will go for .co.uk one when I'm looking for a serious domain.
thanks for suggestions. a friend suggested DNS service provided by http://freedns.afraid.org where one can register .uk.to and thousands of others free. They have other DNS records you can play with like AAAA, CNAME etc