I'm sure there's some old UO fans on here =) There are lots of 'free' servers out there. If you're at all interested in UO I'd encourage you to try out The Second Age. They have done a great job at replicating 1999 era T2A. I've played every pre-T2A and T2A free server out there over the last few years and this is by far the best one. Was even a staff member on another T2A server; it's better than that one!
Easy to join; they have a simple install package you can download that includes everything you need to get connected.
Between the website, WIKI, and forums there is all the information you need.
Always 400-500 clients connected with around 700 during peak hours.
Check it out!