Subway is easy, just go all-out on offense and make sure you raise your Pokemon right, and there's really no problem. Probably the easiest way in terms of time commitment vs. power is Sand. Get a Tyranitar to lead off with, preferably with Stealth Rock if you can x-fer one from Gen 4, and throw more or less whatever the hell you want on it. Follow up with an Excadrill and a Garchomp, and you have a lot of instantaneous power that should leave Subway pretty easy.