Bunsmobile is definetely one of the best burgers in Berlin, along with The Bird, it’s hard to choose between the 2. It’s a food truck, so you have to follow their Facebook page to know where they are, they are often at the Street Food Thursday at the Markthalle Neun in Kreuzberg or at Urban Spree in Friedrichshain and at lots of other events around the city (but mostly the Eastern part).
The staff is friendly, here no number when you order, you’ll be asked for your name. The menu changes often but I can tell you the cheeseburger (with extra bacon) and the Raclette burger are delicious, my favorites! Thy don’t serve fries but roasted potatoes which are also great. Everything is home made, even the buns, the meat is really tasty, everything fresh, a real party for your taste buds. So I can highly recommand you look for the yellowish-greenisch truck and get a one way ticket to Burger paradise!