They both have their virtues. They both have their pits to fall in. Historically, it seems to me that neither is better than the other - as there is no utopia yet(unless you consider Today utopia)- and the goal is to make a world without suffering.
Communism seems like a good idea - why wouldn't you want everybody to help provide for everybody else? - but then why is the estimated death toll, to it's own citizens, from communist regimes 60 - 160 million(160,000,000)? And why does this seem to be the case for almost every communist government?
Imperialism sounds like a good idea too - if your country is to be prosperous, why wouldn't you want to bring that prosperity to the rest of the world? - but then why do these countries always seem to conquer and claim what isn't "rightfully" theirs?
You've asked the opinion of internet armchair experts. This armchair expert says, "Balance". They both have ideals that would help rid the world of suffering. They both have brought suffering of their own sort. There are also many more ideologies than just Communism and Imperialism. Your question is unanswerable, and anyone who claims to be right in the declaration of one over the other should be met with doubt and skepticism, heavily.
You should read The Road To Wiggan Pier. It's by a socialist who hates what socialism has become.
Based on what criteria ? Self-righteousness: (if that's a word) I think they are equal Death toll: I don't know the numbers but I would say communism wins Peace in the country: I would say imperialism wins Hate among country men: I would say communism wins lol Hate for strangers: hum I don't know but I'm tempted to say imperialism wins here. Economic sovereignity of the population: (again I don't know if this is a word) I would say imperialism wins Corruption: I think communism wins this one but cannot explain why. ( human nature i guess) Peace In the world: Communism wins as long as the leader is content with only ruling his country.