Here's a place that looks every bit like an American style bar. However besides cheap beer and Western favorites, it also does Thai food really well, and even regional Northern Thai food! They didn't bother to translate all of those on the menu, but it's definitely there, as well as on their little whiteboard with daily specials. So here's a place where you can have a 30 baht beer (happy hour ends at 7pm), a hamburger and fries, AND a very decent Kaeng Noh Northern Bamboo soup/curry on the side. It even has more exotic Northern stuff on the menu that I don't dare mention here for fear of scaring people off, but DO try the sour grilled spare-ribs. (Naem See Khrong Moo, pictured.)
Kafe is a very long running place and used to get a good mix of local Thais as well as Western tourists, but recently the tourists often have the upper hand, depending on the season.
Most dishes are moderately priced, say 60-80 baht for Thai food and 80-120 baht for Western dishes, though a simple Hamburger and fries can be had for 60. Where you'll really save compared to the bigger pub-restaurants on the river is when you're a beer drinker. They have Chang beer on draft that's just cheap by any standard, and VERY cheap before 7pm.
Kafe is on Moon Muang Road, along the moat North of Thapae. It's in between Soi 5 and Ratwithee Road, exactly opposite the huge Rydges hotel.