My Yahoo, as a portal page. I started using in the mid-90s and have never bothered to change it. It works pretty well for a sports scoreboard, weather, movie listings, headlines, etc.
iGoogle page with ESPN and Yahoosports top stories, weather, and google calendar visible. NY Times top stories, Rotten Tomatoes, and woot widgets if I scroll down (rare).
btw, I hope no one tries to go that page, only to find out it's some lemonparty type website (or full of virus's..btw, shooter or anyone else, DO NOT GO TO LEMON PARTY. DO NOT GOOGLE IT OR ANYTHING)
I start up on blank pages for most of the browsers I use. I think I've got IE on my Windows machine at home (which I rarely use) still set to MSN.com or whatever the default is.
I rarely close all browsers, so it's not terribly relevant. But Google is my home.
I'd say my most visited site on the internet (a much more relevant question, IMO) is Reddit.com. If there's a lockout, I see it sucking up even more time that I used to spend here.
If I were running any kind of bulletin board community, I'd be very, very scared of Reddit. It's just a much more sophisticated way to view user-generated content, and it has the one-stop-shopping appeal of Amazon. I can follow specific communities I choose ranging from Atheism to Blazers to Technology to Dieting to Boise all in one place, and see the most interesting (highly voted) topics from each of those communities on a single page. IMO, in the long run it's going to be very tough for a place like SportsTwo to compete with that.