One with a respectable reputation. Free chats chats and freechat online. You probably do not want to be with a provider that's homepage to a lot of adult sites, etc. This may or may not be a problem to check. Many of these type sites are banned from the major search engines, especially the really bad ones.
Dependability is an issue to consider.
Such as a lot of Server down time, Hard Disk crashes, and server program problems, etc. Stability is another issue to consider. Forever that is - while they last. They seem to come and go fast. If you are looking to establish a personal webpage, save yourself a lot of headaches and disappointments.