Currently, I'm culturing my cells in RPMI1640 or AIM-V (Life Tech.) + 10% FCS or 5% PHS respectively for ten days tops.
It will depend on your intended use.
Typically we add L-Glutamine (final concentration 2mM) and Penicillin-Streptomycin (final conc 100U/ml and 100ug/ml respectively).
For longer term culturing we also buffer the media with Hepes and 7.5% Na Bicarbonate.
If we're growing a new cell line from another lab for the first time we'll also include Plasmocin until we can check mycoplasma status.
Cells are cultured at 37oC in 5% CO2 environment.
It also depends on what cell types you are interested in. If you are looking at T-cells you can consider to IL2 to the medium if you keep them in culture for more than 48hours. We sometimes use R10/50, i.e. RPMI with 10%FCS and 50IU/ml IL2.
I want to culture CD14+ cells from healthy donors for 6 days in a biocompatible environment that induces as little stress as possible, so they do not become immune suppressive. At the moment, that is not happening.