I agree, there isn't any pet I would recommend leaving for that long. Even with fish and reptiles- if the power goes out, or the heater malfunctions you've got a big problem. Most reptiles also need special lighting that must be turned on and off daily. Without it they can get very serious bone problems. You could put it on a timer, but thats one more thing to worry about. I actually know people who have purchased back up generators just for their fish tanks in the case of power outages and storms. Generally they have large saltwater set ups that they've put alot of time and money into. But really, even a small tank costs a bit to maintain and keep nice, I would think it was worth it to pay someone a few dollars to stop in a make sure everything is ok. Plus, if the heating or air conditioning goes out, the pet could freeze to death or overheat quite quickly.
There are some pets that I think need less maintenance, but none that I feel it is safe or fair to the animal to leave it alone for that period of time. I would look for a low maintenance pet- one that you could either drop off at a friends, cage and all (like say, a hamster), or one that would only require one visit every day or two and mostly just to peek in and make sure everything is ok- like a reptile, cat, fish, or small animal. I wouldn't recommend a bird, they are very social and sensitive to changes in their family and their environment- most birds would not do well being carted to a friends house, and they wouldn't like being alone either. They also need quite alot of specialized care, and many will bite unknown caretakers.
Have you considered either hiring a petsitter or boarding your dog? There are some excellent options in both categories these days- from luxury dog camp/spa/ hotel facilities, to pet sitters who will visit multiple times a day or even live at your house while you are away. Generally you do have to book in advanced, but they are reliable, knowledgeable, and animal lovers.