I'll get the facts over with first, they have changed locations (just a couple doors down the…read morestreet) from where they were 5 years ago. I was nearly devastated thinking they no longer existed! Don't worry, they still do but now have more space and a small biergarten :) Also, price hasn't changed, still a few euros for a döner. Now on to the more important details....
Istanbul Imbiss makes the best Döner in all of Germany! This might be more of an opinion than a fact but to me there is no doubt about it. I would get their döner at least once a week while I was studying at the university, I just couldn't help myself. I find myself often craving an Istanbul döner, no one makes it quite like they do! I always order the vegetarian döner with cheese and get all the veggies and the yogurt sauce including, of course, "etwas scarf." What I realized last time I was there, is that the secret is mostly in the sauce, then again I love the cheese, it tastes nothing like I've had before!
Ok enough ranting, try it yourself!!