Ghostsliders! Man, I loved this show. I can barely remember anything about it, but I used to watch it all the time when I was a kid.
The only characters I can remember, other than the Ghostslider, are Jamal, the black guy, and Alex, who wasn't black.
It kind of sucks that they never told us what or who the Ghostslider was. I really liked the plot device, though--a ghost who can only see writing, brilliant.