CompuServe worked well for me this summer in France and Spain; but I won't recommend it over any others for the simple reason that I have no knowledge of any others.
The access 'phone number available from the CompuServe program itself worked; but we had to call the French HelpLine number to find out that to get the WWW Server you had to configure CompuServe to use the "National" network and not the "CompuServe" network. Very confusing. If all you want is the use of the Mail Server you may get by with Outlook or Outlook Express but there may be a problem because CompuServe uses a script file to log on. Before I go again, I shall experiment more here in the UK without using CompuServe's own software.
I spent a small fortune in mobile 'phone charges but, as luck would have it, it was worth it from the money we saved on our next holiday by being able to rearrange it!
I'm talking here about CompuServe 4 not CompuServe 2000.