Agreed.
Rhinogobius are great, but do bear in mind most are coldwater to subtropical species so they'll need an aquarium maintained at the right sort of temperature, typically room temperature.
Stiphodon are tropical fish, yes, but they're from mountain streams so need a "hillstream" type environment similar to that you'd use for hillstream loaches. Lots of water current, lowish temperature, and plenty of oxygen. They're fiddly to feed, too.
There are some nice sleeper gobies coming out of Southeast Asia and New Guinea. Sleepers tend to be easier to feed than regular gobies, though they are also more predatory as well as territorial. The pick of the bunch are surely the
Mogurnda species if you have the space for them. They're hardy, adaptable, eat anything (mine enjoys cichlid gold pellets), and get along fine with robust community fish. Other choices include the Black Toraja Goby (
Mugilogobius sarasinorum) and the Golden Nugget Goby (
Giuris margaritacea). In small, soft water tanks, the Peacock Gudgeon (
Tateurndina ocellicauda) can be fun to keep and breed. In the UK, the larger branches of Maidenhead Aquatics, among others, seem to get these sleepers fairly frequently.
Cheers, Neale
There are LOADS of species of freshwater gobies!