Well Maiden solos are consistently excellent, you need to dig hard and deep to find ones that aren't. Most of them are tradeoffs so it is hard to crown out a single guitarist solo. Within that limit, SIASL and 1st Powerslave solo are the top dogs.
And not all of them compete. For instance, a lot of people here love Blood Brothers solo. I think it is very good. However it is just a few bars of repeating the melody. With a lot of feel, great sound, great execution, but it does not compare to a 1 minute solo.