4-stars. great food and services. thalasso center with an interior 30'c, salt water pool, another outside and private beach. 3 restaurants. deco from the 80's but not expensive. 5 minutes away from the medina and near all transportations.
Midrange
$$
Hôtel de Paris
Spotlessly clean if rather austere hotel near the main entrance to the medina. small singles from tnd 13.
Don't compare the category directly to european hotels. Expect to take a star or even two from these hotels. 4/5 star hotels are recommended.
Budget
$
Hôtel Gabes
12 rue de paris, in the medina. tnd 7.5 for a spartan single room; but good location and trustworthy staff.