Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Siófok (43% of total searches to Lake Balaton). The next most popular destinations are Keszthely (29%) and Balatonfüred (29%).
KAYAK users have found double rooms in Lake Balaton for as cheap as $79 (Keszthely) in the last 3 days. The average price is $231.