Gmail

Two things:

(1) I've switched over to Gmail and love it. The "labeling" as opposed to "folders" takes a moment to get used to, but it's tremendous. (Its custom filtering is also great.)

(2) And as far as spam is concerned, it has a tremendous spam blocker: The best I've seen (puts Yahoo Mail to shame.) I also believe that I get more spam than anyone. I just cleared out my Junk Mail - which had over 5,000 in it - and there's the fresh and clean screenshot above. I'll post another at the end of the day and week to let you know how much it catches. (I just looked and it has already captured 3 in the last couple of minutes.)