video of 1992 Clinton veep speculation on The McLaughlin Group

[Never]

I notice that a sign of a winning campaign is when the media does not know who the running mate is before the announcement. I remember the media knowing for certain Paul Ryan to be the pick in 2012.

No.  Nobody expected McCain to pick Palin, and Biden was talked about as one of two or three possibilities for Obama.

True, but even though Biden was ultimately picked, it seemed like the media had Evan Bayh as their "front-runner" for the VP slot. I kept seeing rumors about him pop up more than Biden. Anyhow, I see what you're saying. It's a good point.

[Never]

Which potential Clinton running mate would have maximized the chances of the Democrats winning the White House a third time in 2000?  Would any of the others have done better than Gore did IRL?

Few of these seem very good for the 2000 election. Maybe Bradley to keep a few of the party's left-wing loyal, or Wilder to offer his home state of Virginia and a lot of media attention for his race. Harkin seems to be a safe but boring choice who would ultimately fail to win the Dems a third term, Kerrey might only amplify Clinton's marital issues, Mitchell's old. Rockefeller might offer something in the way of West Virginia, but I doubt his ability to expand on Gore's states beyond that. Tsongas would be dead and I know nothing about Wofford other than what I just read on Wikipedia, and he's friggin' old.

Bradley might not have been negatively affected by Nader's candidacy to the extent Gore was. That could have helped in at least one state that Bush won in 2000, which would really be the only necessity for victory.