Favorite Iron Maiden riff?

Main riff of Rime.

And the bridge riff in The Duellists is occasionally peeking through my brain as well.
 
I love pretty much all of Infinite Dreams, as a bass player thats a great song to play, the riff towards the end of Sign of the Cross i love too, i wish i could hear that for the first time again
 
Well my favorite part to play on guitar is

Pre-chorus-riff:
Running scrambling
E-------------------|-------------------|
B-------------------|-------------------|
G-------------------|-------------------|
D-------------------|-------------------|
A--5-7-7-7-7-7-7-7--|--5-7-7-7-7-7-7-7--|
E-------------------|-------------------|

flying
E-------------------|-------------------|
B-------------------|-------------------|
G-------------------|--5-4--------------|
D-------------------|------7-5-7-5-4----|
A--5-7-7-7-7-7-7-7--|----------------5--|
E-------------------|-------------------|

Rolling turning
E-------------------|-------------------|
B-------------------|-------------------|
G-------------------|-------------------|
D-------------------|-------------------|
A--5-7-7-7-7-7-7-7--|--5-7-7-7-7-7-7-7--|
E-------------------|-------------------|

diving going in again
E-------------------|-------------------|
B-------------------|-------------------|
G-------------------|--5-4--------------|
D-------------------|------7-5-7--------|
A--5-7-7-7-7-7-7-7--|-------------------|
E-------------------|-------------------|

My favorite to listen to is Sea Of Madness.

The hardest Maiden riff to play is easily the begining of Back in The Village.
 
Most Maiden riffs sound different, but enough of them sound alike enough that it's sort of a 'characteristic' (due to lack of a better term) of the Maiden Sound.

My fave maiden riffs:
Intro to "Only the Good Die Young"
Intro to "Die with your boots on"
The part of "Rime of the Ancient Mariner" right before (and during the first part of it) the guitar solo
Intro to "Wasted Years"
The part during the solo of "Heaven can wait"