Tonkichi Seafood (seafood, really?)
I'm not sure why this place is called Tonkichi Seafood, seeing that there really isn't any seafood on the menu aside from the ebi furai. In fact, I was recommended this place by a Japanese journalist here in Singapore not for "seafood," but for quite the opposite: cheap but good tonkatsu (breaded pork). And it's well deserved: the pork is deep fried to a light and lean crisp but still tasty and tender. They also give you unlimited refills of a very finely shredded lettuce, in case it helps your conscience after eating all that fried pork. I haven't tried much else on the menu here aside from the curry, which isn't the best that I've had, but there aren't very many places to get Japanese curry around here (I was disappointed with one curry place near Raffles City as they spiced it up for local palates a bit too much).
Anyway, the tonkatsu here is really worth coming for, and is definitely very affordable (in the realm of Japanese food, anyway). But try to avoid this place (three locations: Isetan Scotts, Ngee Ann City, and Suntec) on weekends as it can get pretty packed.