We did not spend too much time in Laos. We were only in Luang Prabang. Here are the recommendations from our trip:
We stayed at Madison Delabua (maison-dalabua.com). The service was excellent and the hotel had a beautiful lotus filled pond in its court yard. We would recommend staying there.
We would highly recommend eating at Tamarind which serves delicious high end Laotian fare. If any of you are interested, the restaurant also does cooking classes including trips to the local market.
Three Nagas was also a really nice restaurant.
There are a lot of elephant sanctuaries in the are where you can ride, feed and wash animals. I would recommend Nam Ou Elephant Farm, which from everything we heard takes the best care of their elephants and provides you with the most information about them.
We would also recommend a visit to the Ock Pop Tok Living Craft Centrex for a learning experience about local crafts.
Just wonder around the town for a bit. Its not very big but there a lot of cute little temples and monasteries.
The main street has a night market which is mostly filled with souvenirs but there is a turn off the main street which takes you into the food section of the night market. The food portion is much more authentic. Try a little bit of everything. I would especially recommend the local river fish which they grill using bamboo sticks right in front of you.
In the middle of the town there is a long staircase up to Pho Si hill which has great views over the town and surrounding areas, especially at sunset.