Avg. price/night: £186
I stayed at Loi Suites for 3 nights in a triple room whilst visiting the Iguazu falls. As the pictures show, the hotel is luxurious and has a wonderful outdoor pool area. Having visited Iguazu previously, I can honestly say that hotels of this standard are very rare in this area despite it being touristy.
The hotel is located close to the Argentinean border and is a short drive from the falls. Both the Argentinean and Brazilian airports are close by and the hotel can arrange for taxi pick ups and drop offs wherever you are going.
Something definitely worth mentioning is the restaurant. The town of Iguazu is, in my opinion, nothing special and guests are better off eating in the hotel restaurant. The menu is extensive (steak, seafood, pasta and 4 or 5 vegetarian options) and the food is delicious and reasonably priced (I think the most expensive thing on the menu was £15). We ate here every night during our stay. There is also a less formal restaurant serving burgers, sandwiches and pizza which is open during the day and in the evening.
The pool area is great and is big enough for you to have your own space even when the hotel is very busy.