Five? Well, I would like to have a little from different eras, and of course some of 'em would have to be rarely played (or never played) songs. Let's give it a shot.
Caught Somewhere in Time
Paschendale
Phantom of the Opera
Only The Good Die Young
Alexander the Great
There we've got two songs never played live, a classic opener which unfortunately hasn't been played since Somewhere On Tour, the greatest song of the 6-man era and the greatest song from the Di'Anno era. This would make for a 40-minutes long eargasm.