Heng Heng guest house. It`s like a NA motel. You can park in front of your room. About 300 baht/night. It`s usually 100% Thai staying there. Not too far from the Watthana Hospital.
N 17.87511 E 102.73495
Mut Mee guesthouse is a fun and relaxing place, with character (and sometimes "characters", Marco dixit ). As a « budget » recommendation from Lonely Planet, it has quite a good occupancy. Various prices from dormitory to Bungalow. I paid 680 THB for bungalow.
Hotel Khong Damant. Fantastic location just east of the city 1km. Clean, new, large rooms with very nice amenities. Riverside location with a view of Mekhong just outside your balcony. Nice breakfast, great hosts, immaculate grounds, well-built, quiet, with a gazebo on the riverside for card games and beers. Where I was, and what I was doing when taking this photo. Group of four of us only ones there. Just lovely.