Nintendo. They had a lot of new games to show off and proper reveals of some already-announced games, with actual gameplay in most of the trailers and a few in-depth gameplay demonstrations, and a lot of exclusives.
MS could have had it since Sony wasn't present this year, but they decided to play it safe. It was a decent conference, but not outstanding. While we did get official confirmation of Scarlett's existence and a very basic description of what's going into the system (like what Sony already did with the PS5). There were a lot of games announced, but there was very little gameplay footage spread among the videos, and only a couple of new announcements were exclusives. I guess they didn't want to reveal too much to let Sony counter later in the year. In any case, they're clearly holding back for next year's E3.