Ivy Grill(vasaplatsen 2) is a god place to hang in the bar and start up, olso god food.
Nightclub Lounge is nice on saturday.
Wendsadys at Nivå are a farly god place.

Anyway Gothenburg sucks on week days. Not much peopel out.

Restaurant Vasastan is also pretty much ok.
Gotenburg is known for the nightclub the garden(Trädgårn), it have seen better days. Its all about tast and what you like.