Fire Emblem: The Sacred Stones - Village of Silence
Not a particularly difficult map, in fact I consider it to be a breather map after Eirika's first two exclusive chapters (on Difficult mode), it's just a really tedious map to get through. Think of the longest, driest, thickest turd you've ever crapped out, and that about sums up what it's like to squeeze all your not-fliers through this map. It also has Asshole Reinforcements, because of course it does, and it caps off with a mildly long-winded exposition dump. Yeah, it's easy to see which route got all the good level design...
Honorary mention to Scorched Sand. It's a rout map, it's the obligatory desert chapter, and nobody likes desert chapters to begin with. There's a Silver Lance Paladin in the south that tends to hold off on charging you until his buddies are in range to join in the fun, lending that part of the map a decent amount of intimidation factor. And Valter is just a right prick if you're not careful with how you deal with him. I'll give this map credit for one thing though, it's one of the few desert chapters where you can really take advantage of the sand. You can make some great choke points with it.