I truly love this piece from you! My favorite of yours indeed!
Any reputable photolab with good inkjet printing credentials should do well. 'Just' need to match color profiles (this piece doesn't look like it has out-of-gamut colors but it doesn't hurt to check) and make sure they understand pixel art should only be resized nearest-neighbor, integer factor.
Needless to say this is a fav, however I agree with Delicious about composition.
dammit now I've got to get meself a new brain. MINE IS BLOWN
The monster is absolutely superb! The forest, leaves and grass are all wonderfully done.
Very lovely to look at.
The giant is ace. Composition seems a bit odd though, I just end up staring at cliffs in the background. The amount of work put into this is alone worth a favourite. The outcome is just as magnificent as the devotion!
Simply amazing. I couldn't believe it was PA until I zoomed in.
Yes!!! It's done! This is truly jaw dropping.
While it's not my kind of thing I can't help but be impressed by the sheer patience and hard work gone into a piece this large and finely crafted.
i agree but i wouldnt know of a proper company that would print pixelart
You should consider making prints of this available somehow. It would make a georgous piece of art hangin on the wall.
This is simply perfect. I can't wrap my head around how dedicated you are to each piece.
OMG is this PA? This is so f*** amazing. Congrats!
Dangerously masochistic
looks sharp though. Dig the area around the face of the colossus.
Beautiful man. The composition, colours and technique are brilliant.
I absolutely love it. There are lot of hours put on it, i can see that! Very nice job :D
400000 pixels full with detail...so muuuuuuch ;_;
Congratulations on writing PJ history. 
Though I must ask, would you really not consider fixing the last rough areas? I was not trying to look for them, but they do distract.
What I found should be less than half an hour to fix, though I can understand that you will see much more and get frustrated 
Ahaaa, finally! It is booteful work, and I'm glad you have finished it :)
OH. MY. GOD.
I literally was wondering where this went yesterday afternoon. It's beautiful :')
[EDIT]: DAMN YOU CYANNNNNNNNNN
!
IT'S FINALLY DONE!
xD You should update your avatar now.