The most obvious bunking-down option hereabouts is this pleasant roadside place, a friendly and recently renovated lodge by San Rafael Falls. Rooms are modern and include all creature comforts. The nine-hour route up Reventador starts nearby; ask about the chances of tackling it or other hikes in the vicinity. There’s also an excellent restaurant here.
Any bus from Quito or Baeza to Lago Agrio will pass right outside the hotel.