It is true the Galilee is crowded with early synagogues (Peki'in, Gush Halav, Meron, Amud, Baram, Navoria - just to name a few). The most impressive site I've been to is probably Capernaum near the Sea of Galilee also known for being the site of Petrus' house. The synagogue resembles a well preserved Roman temple and is also beautifully located near the shore. Another impressive building is the one in nearby Korazim. Synagogues with original mosaics are Beth Alpha, Hamat Tiberias, Maruth and Seppharis. These show the strong Roman influence on the Jewish culture of the time by combining Roman gods in the depiction of Biblical scenes. I haven't been to Maruth but the other three are impressive and probably unique. I think this nomination could fill a gap and be justified.