I got the following information on Brasilian board and most of these places are within a couple walking blocks from the main bus terminal and the ferry (Barcas) landing in Niteroi. I don't suggest taking a taxi as it would cost at least 50R from Zona Sul.
There are vans that run on Ave. NS Copacabana for 5R that will drop you off in the general area. The main road in front of the Ferry is called Avenida Visconde do Rio Branco. There is also a large shopping center called Plaza Shopping Niteroi. So, it is not like you are venturing into a slimy area. There are lots of police patrolling the area and I felt very safe walking around there.

You can take the metro downtown as well, then take Bus #100. It is cheap, like 2.60R. The ferry is roughly the same, I think 2.50R. The ferry takes almost exactly 20 minutes and unlike everything else in Rio, it runs on a fairly consistent schedule. During the day, the price of the view and relaxation of the water is worth the ride alone.

Why am I posting this? Because, it is cheap alternative to Zona Sul. And the 'ole saying of "nothing ventured, nothing gained". On my way back from this area in a van, we picked up 2 hot looking garotas. I thought they were "normal" girls. Only for them to be asked to be dropped off right in front of Barbarellas (where they walked in). Not to say these girls work in a cheap place during the day, but they might. Just like VM girls have been seen in Help at night. Sometimes going off the beaten path can pay dividends.

Termas Excentric Rua Conceição, 132 / 202 - Centro - Niterói
Tel: (21) 2722 3759 / 2620 7547

Termas Relaxa

Termas Casablanca

Gold Club - Amaral Peixoto, chegando na delegacia da Civil

Oasis - Do lado a Excentric, toldo vermelho

Club 16 -
315 - Se eu não me engano, barão do amazonas, entra na rua da club 16 e depois vira a primeira ou segunda a direita, de costas para o terminal.
128 - Atrás da rodoviária de niteroi
Passando pelo Club 16, uma rua depois da que se entra para a 315 tem outro, eu não sei o nome.

Castelinho - Passando por trás da Ampla, passa a cantareira, passa a praça depois de onde tinha um clube de Cart. É onde ficava uma boate normal, a Skipper, isso a muito tempo atrás.

177 - Na rua Marechal Deodoro, número 177. Um amigo meu da Polícia Federal me recomendou não ir lá a uns 4 anos atrás, não sei como está hoje.

Vertical Villa Mimosa - 15R:
Amaral Peixoto 327