In terms of Sig Arenas I've been using this one a lot lately:

Bowser's Castle

Filled with winding streams of lava and countless traps that usually involve spikes, this menacing abode is not to be reckoned with. The opponents can travel to over 100 different rooms, each room with a different purpose, depending on how creative the battlers can get. It is surrounded by a lava moat and has flat arena on its ceiling, upon which the battlers will start. There are also many illusions and secret passageways into different dimensions. Due to a tantrum our friend Bowser had recently, the castle is under repair and is currently deserted, and only two alternate dimensions can be acessed: a simple narrow dock above a vast sea, for water pokemonnnssss of course (they cannot be accomodated in the Castle itself, seeing as the swimming pool is filled with greenish magma crap) and a small series of cloud platforms in the sky. If you are to fall from the clouds, 9% damage. Fall from the dock, 8% damage. Fall anywhere else that isn't into magma 9% damage. Fall into lava/magma/greenish goo 10% damage. Get hurt in any other way 10%.

And I just got a new ASb team member, Exeggcute M, Akon! Everyone say hi!