My all time favorite band. I didn't mention them because the OP said "rock" only and I figured he didn't want metal.
But seriously, you can't tell them apart? Their styles are quite different. Adrian has the more structured solos with the wider vibrato, while Dave has the more Hendrix-y sound with less bite from using his neck pickup.
(I'm a total Maiden geek. I have a tattoo, play in a tribute band, etc )