Personally, there are many great spots to watch illuminations from. The dessert party I would not pay for. You can view illuminations from the bridge between UK and France. My personal favorite spot is just to the right of Germany. There are quite a few benches and it usually isn't too crowded. The only key point is I would pay attention to the direction of the wind so you aren't having smoke blown at you. My location in Germany is located southeast so for most of the year the smoke will be blown away from you.