The most challenging maps for you.

"The Viking Uprising",

Do you mean "Forward, Vikings"? (maybe it's just different translations...) If so, there's nothing particularly difficult about the map. It was used in the "Clan Tournament" on our portal... The winner completed it in 2 weeks ;) And, of course, starting from Reykjavik. And I personally spent a little more than a month of game time on it - and I consider this a rather mediocre result! (for myself...)
And how long did it take you to complete it?
P.S. If, of course, that's the map....