I chose Oxygen as a place to rest during my journey in Taipei. The location is perfect, it is near Taipei Main Station, and you just need about 10-15 minutes walking to travel some special landmarks in Taipei, for example the Taipei's Presidential Palace, Xi Men Ting night market, and of course on your road to these destinations, there are lots of shops to go shopping and food stalls where you can taste a wide range of Taipei food. Besides to the perfect location, Oxygen also offers a 4-star good service, with clean bathroom, a nice tiny space (I hope it would be better if the bed was bigger), and no any problem with roommates; there is also friendly and helpful staff (they can speak English!). Especially, the price is quite cheap for the good service (I remember that I just paid around NT 600 for 2 nights at Oxygen).
To sum up, for me, a good choice if you want to stay in Taipei on your solo trip. Highly recommend !!!