I have 5, work email and home email get checked several times a day. Yahoo pretty much daily too since it pops up when into Messanger. Two Hotmail that I check periodically, mostly to clean out the spam.
I have six thru my WebTV - one being my "main" e-mail address - and the other five I use mainly for storage. I also have my ISP address and a Yahoo account, but can't use them right now b/c the computer's down..
I usually check them just about every day, but not always: it depends upon how hectic the day is..