This is more a question of personal choice. Ask yourself what do I want out of the tank.
My own choices would be a 40B or a larger 70 gal tank. I find that the 12 inch front to back dimension of the 55, 40L and 38 make them very difficult to aquascape and get something that look decent. The 18 inches front to back on a 40B or 70 let you really do something.
As for ease of maintenance, I don't think there would be that much difference between any of the tanks. You still got to clean the filter, scrape the glass and so on. Only if you went a lot smaller would you save a lot of work.
My own choices would be a 40B or a larger 70 gal tank. I find that the 12 inch front to back dimension of the 55, 40L and 38 make them very difficult to aquascape and get something that look decent. The 18 inches front to back on a 40B or 70 let you really do something.
As for ease of maintenance, I don't think there would be that much difference between any of the tanks. You still got to clean the filter, scrape the glass and so on. Only if you went a lot smaller would you save a lot of work.