I am looking for xen based vps. Since there are lots of linux dists on the market. anyone may help me to chose the best dist? I am not expert on linux and looking for the one that could be rock, speedy and easily maintained on xen based VPS. thanks for any suggestion.
I'd say Ubuntu over Debian (if available) nowadays - Debian's stable releases usually take way too long to update, while Ubuntu is usually quite up to date and offers very similar functionality to Debian.
My (personal) primary choice would be CentOS though.
CentOS is very popular, going with the popular OS have advantage like better support. I used to use FreeBSD on my hosting servers as many say it is good, i too like it, easy to manage, but when it comes to cpanel servers, it start creating problems, now slowly moving to CentOS.