Just found this thread.. My three favorites:
Banteay
Requires: 1 BftU + 1 TJ
Riven II
Requires: 2x BftU +glyphs
Flogging for Two
This is a modification of Piherculis's three-player 'Fulcrum Flogging' map. Modded to be a two-player map.
Requires: 1 RotV, 2 RttFF, 4 single tiles
~Z