I think the other reviewers must have stayed in the dorms (which we didn't see). For a young married couple who want a private, en suite room and appreciate cleanliness, comfort and quiet within easy walking distance of amazing food and sights, this place is Eden. We never saw a single bug and I can't imagine seeing a cockroach here.
The Silom Art Hostel is one of the best hotels we have EVER stayed in -- and it cost us $40 USD a night through Agoda.com! We're from South Florida, and the same accommodation would cost $300+ in Miami. This place doesn't have many reviews because it's very new, and amazingly it was quite empty during our four-night stay. At first, I was wary because the facility is so nice. I thought, "There must be a catch." But if there is, we never found it. The building is located down a quiet alley off Silom Road (slept great!). The Skytrain and numerous yummy restaurants are within easy walking distance. (Try the amazing Pad Thai at Suzy's in the lane across from the Indian temple). Stepping into the lobby of the hostel/hotel, you feel like you have entered a modern art museum. Colored glass bottles and construction worker hats have been brilliantly transformed into light fixtures. The sofas look like aluminum barrels cut in half with rubber boots playfully attached. Everything is colorful, funky mismatched -- and clean.
We had room No. 308, ("King Bed en Suite), a spacious, spotless room with a very comfortable king-sized bed (storage lockers ingeniously built underneath) a desk, a funky sofa, space for hanging clothes, a small balcony and attached toilet and large shower (with reading material afixed to the ceiling!). When we walked in, I ran around the room examining each feature with delight. I was so happy - especially after paying $85 for a tiny room in Singapore. Each day when we returned from sightseeing, there were fresh towels, chilled bottled water and a made bed awaiting us. The in-room AC is adjustable and quite powerful. The staff is friendly and helpful. I didn't want to leave. I wanted to move in - or at least decorate my future home like this fun, artsy hotel. I can't complain about anything. Superb.

Additional features: A beautiful rooftop deck, do-it-yourself laundry (30B for wash / 40B dry / 10B for soap), free (fast!) WiFi that works very well in the rooms (I even uploaded a video to YouTube) plentiful reading material to borrow, indoor hammocks, a computer area and drinks for sale ($1 canned beer!) Elevator. Dorm rooms available.
*Don't forget to greet PeePee, the adorable, mohawked mutt that lives at the laundry shop at the end of the alley.

Nice design, clean and comfortable. Friendly staff. Not much in the neighbourhood, like in banglamphu, but only a 10 minute walk to the skytrain. Got almost everything, working hot shower (as far as needed in bangkok), laundry and quiet, but friendly atmosphere, alas no food/restaurant.

Unique if sometimes strange styling, quite spacious room (stayed in a double) with all the must-haves: free and fast WiFi, comfortable bed, shower (difficult to adjust).
Quite clean but that doesn´t save you from the occasional coackroach (hey, this is Bangkok !!).
Friendly staff, especially at the reception.
Because of the open staircase it could be noisy during the night (equipment and music at the reception).
Unfortunately without any atmosphere- probably it´s just too new ?!