Round One Intangibility off.
Round Two Intangibility on.
Madara and Aizen have their current powers.
Aizen is physically the weakest in this battle and could easily be picked off by any of the Admirals before he has any chance to react. As for Madara, he could provide a difficult match for any of the Admirals if he were taking them on solo. But with the numbers game being in favor of the Admirals (with or without Logia intangibility) who are each quite powerful and have yet to be seriously challenged in One Piece, Madara's getting overwhelmed here.
@taichokage: Meteors would kill off Aizen and Madara (latter isn't in Edo form here), giving victory to the Captains by default for scenario #2 since the Logias would likely survive. Otherwise, would be a draw without Logia intangibility. And if we're going under Aizen's current self before he was defeated by Dangai Ichigo, he doesn't have Kyouka Suigetsu in this match.
Also as usual, I'm not buying the immortality argument with Aizen.
@Aamir: If you're gonna operate under the assumption that Madara has full access to abilities with the Rinnegan when he has yet to demonstrate all of them, then I can apply the same logic with the Admirals who all have Haki and should roughly be at the same level of statistics as one another.