There are several good endings. The one with "Twist & Shout" played on the last tour was great, and also the way they ended the show in Stockholm 2000, with Keep The Faith.
But still, the ultimate ending are with LOAP, that's just so cool! In close second I would have to say the ending with TAALS, because of the emotions..

But on the new tour? Can't say as maybe I would like a new song to finish the show, otherwise I think I would go for an ending with LOAP or a ballad like Never Say Goodbye, There For You or in the likes..