Generally I'm not in favour of House rules except in scenario play, but we have got just a couple that are now in constant effect.
Windows
* You can shoot out of a window if you are adjacent to it.
* You can shoot at a target adjacent to a window, but they gain cover.
* Adjacent characters seperated by a window follow standard adjacency rules (i.e. must attack, AOO, no cover).
* Windows can be destroyed by Satchel charge.
AT-AT
* If an AT-AT Driver is within 6 squares the AT-AT can spend a move action to move 1 square sideways or backwards.
* Massive - ignores walls when moving.
* Damage reduction has a save 11, on a failed save it is only DR10.
* When attempting to STOMP a character with the EMPLACEMENT SA the save is made before the AT-AT enters the target square, on a successful save the AT-AT must end it's move.
The only other House Rule we have contemplated is allowing characters to move around the board using the Lifts.