XXL....RHM / Modular Airport / Trams imo... THE most important mods for building realistic cities! I find myself repeatedly starting new cities in XXL and then losing interest, simply because these mods are not up to par or don't exist yet. XXL's realism will never be compatable with XL (esp with CJ's & Competions) until these 3 mods are working at 100%. Please, please, please....(to infinity and beyond).