I got spicy currywurst. It had a decent little spicy bite to it. I prefer my currywurst always with…read morea bit of kick along with the curry flavor, so I wouldn't order anything "plain" here. Be sure to order fries as well or else you will only get served two sausages like I was. One of the best currywursts I've had, although this is in a sit down restaurant setting.
To wash it down, I recommend Früh Kölsch. I know I know, it's Dusseldorf, one ought to be drinking Altbier. Personally, I prefer Kölsch and it just fits better with the spice of the currywurst.
In the end, currywurst is really a cheap street food. If you want to pay a bit more and sit down with a group (there's outdoor seating too), then this is great stop while walking along the Rhine.