Enough for your rental deposits and first months rent, utilities, groceries, transportation (including insurance/fuel/or other transportation) plus three months budget to cover any unexpected unemployment. If you own a car, consider banking enough to cover unexpected repairs/insurance deductible.

Also, if one is looking to move into a shared living space, remember that everyone on a lease is solely responsible for the monthly rent. Landlords don't allow you to stay because YOU paid your portion.