This one http://tiny.cc/gVVNn is close to city center and subway adjacent. It has double rooms and you can see reviews on the website provided.
The next one http://tiny.cc/Bbc0X is in a newly refurbished part of town, it is also subway adjacent.
Last but not least http://tiny.cc/vEqUP this one is the middle of historic downtown Lisbon.
Hope it helps and have a nice trip