Moreno Hotel is a solid choice for Bs As. Cool locale and décor that really speak to the Bs As vibe, very reasonable price (125USD/night), competent staff, big, clean rooms with free wifi, comfy bed and bedding, etc (btw, for Mac users, note that it doesn't seem that anything bigger than a 15-inch laptop will fit in the room safes). It's also nice to have the free breakfast in the morning. (Yes, there are the same offerings every day and the coffee is not great, but there is a good variety, from the healthy to the decadent. And, of course, it's nice to be able to just walk upstairs for the first cup of the day.) We asked for a quiet room and, by and large, got one (room 23). The "by and large" stems from the fact that, about 5 days into our 7-day stay, there seemed to be some hotel-related construction that started around 8. Not that bad except that, per the local lifestyle, we'd STARTED to have a big steak-with-wine dinner around midnight the night before, so 8 or 9 felt early. We didn't really press the matter, but we did ask about it and got a kind of mediocre response. Anyway, back to the good, a last note: Even though Recoleta and Palermo are so touted and it's easy to get out of this neighborhood using the Subte, don't forget to walk around this (the San Telmo/Nicolas) neighborhood and try out some of the great places right around there -- Bar Seddon, Bar El Federal, Bar Sur, Territorio (with local/Argentine Antares beer!), Papa Deus, Petanque, Desnivel, little stand-up sausage and steak stands, and much, much more.

Great location nr Plaza de Mayo and in the San Telmo district. Very close to the Sunday antiques market.

Modern decor in art deco style, very clean rooms and friendly staff.

Great rate on their own website - we paid US$95 per night plus tax.

My Boyfriend and I stayed here a few times while travelling in Argentina and each experience at The Moreno was great. The first time we arrived at 8am after a long flight and the staff could not have been nicer, checked us in straight away. Although not fully finished (Bar Restaurant Theatre etc to come) I really don’t think we could have picked a better place to stay in Buenos Aires. The staff are professional, incredibly friendly and helpful. The rooms are large and beautifully furnished. The beds are comfortable and the showers are amazing! It was such a pleasant place to return to after a long day. The hotel provides a basic continental breakfast. When this hotel is fully complete with its bar & restaurant I have no doubt it will be the best in town. We loved our stay in this cool art deco style hotel, great location at a fantastic price. Would recommend it to anyone!

We booked through the hotel website - they offer a best price guarrantee, and had an extra large room, which was in fact massive, we stayed for six nights.
The hotel is still not fully open, there is no restaurant, no room serivce, no bar, no theatre, no rooftop BBQ.
What is open is the rooms, reception and the breakfast room on the roof.
If you dont mind that most of the facilities arent there yet (June 2008) then what is there is excellent, the rooms are lovely, nice art deco theme, good lighting, excellent bathroom (though a little short on hot water) good sheets, big work table, couch, wifi and a mini bar.
Reception was very friendly and helpful with good restaurant recommendations.
In lieu of room service reception offered a takeaway menu from a local pizza place - without a doubt it was the worst meal i have had in BA. The breakfast was not much better, a gaggle of staff eating and chatting and paying no attention to the diners, and a very very basic breakfast, just half filled bowls of cereal, toast, yoghurt and few pastries. no fruit no eggs, a very basic breakfast considering the price of the hotel.
over all we would stay there again, because the rooms are nice and the location is great - but we will wait till the place is fully open!