I vote for fileserve because their File Manager is:

1. Fast and efficient.
2. Started the Concept of the copy feature and execution of this and other features is brilliant.
3. Has everything at the right place and so its easy to access and use the features.
4. The design and style of the file manager is great and better then other hosts by far.

When you look at Fileserve's file manager you can see that it was designed by professionals and not by some kids in a basement.

If i had to vote for a host apart from these four, i'd say RapidShare just because of RUM.