This is a course map I really like and it's a map pretty much everyone can do!
http://gamebanana.com/css/maps/141529
mg_fred_v4
It's an obstacle map and takes about 35 levels!
And as PTK already suggested before:
http://gamebanana.com/css/maps/163179
mg_hideandgoshoot
And the previous sort of version of it:
http://gamebanana.com/css/maps/57085
backalley_run_v2
Maybe Wipeout can be removed? By playing on the server I noticed people generally really dislike it!!