I really like this place. I had been craving a proper 'deli' type restaurant but was previously unable to find anything of the sort in Taipei (Taiwanese cuisine isn't exactly known for its sandwiches). Enter Dressed. The restaurant has a 'salad bar' sort of format, where you can create your own salad or wrap. Their list of ingredients that you can put in the salads is quite extensive, including many kinds of cheese, beans & nuts, and many different vegetables. Not all the ingredients are vegetarian/vegan, but with the 'make your own' salad/wrap format, it's very easy to create something that suits your taste. They also have paninis and pastas. The bread that comes with the salads and sandwiches is really quite good compared to what one would normally find in Taiwan. The vegetable panini is very good.
The only reason I don't go there more often is the price. It's really expensive for what you get. Salads start at around 200NT, and if you want to add things like goat cheese or portobello mushrooms, you might be looking at 300NT+. Also, while they have a nice list of dressings, they hardly put any dressing on the salads -- sometimes you can't even taste it.
Overall, it's probably the best place to go for salads and sandwiches in Taipei, but could be better/cheaper!
Cons: Expensive, Salads need more dressing