My friend and I stayed at Tree Top Eco Lodge for a week because we loved it so much. It has wonderful and helpful staff, a beautiful terrace, $7 private rooms, and excellent Wi-Fi.
The lodge is perfectly located in town. Just a few blocks from the main street. We stayed in the low season, so we can't vouch for the atmosphere too much.
I have spent six months in SEA, and this is one of my favorite guest houses.