Do NOT use Armor-All or that STP shit for "conditioning" the interior, bro! You're going to be so sorry.
Like most people in here say, use leather products. For stubborn stains that really won't budge, I'd hate to say this, but if all else fails, you might be able to get that out with acetone, though LET THIS BE FAIR WARNING... this stuff has the propensity to melt your vinyl interor components, and ESPECIALLY painted surfaces! Some household-grade cleaners that would otherwise be detrimental to the "health" of your quasi-leather surfaces may work... such as, perhaps, comet, which does work wonders all the time for me. But like I said, this is just for intense stains. I know how it is with a leather interior. Just remember to condition heavily with a non-greasy conditioner.
And just FYI, the only things real leather in your car are the center portions of the seatbacks and bases. Everything else soft is either vinyl (door and seat sides and bolsters, headrests, and dash parts) and rubber (airbag covers).
... And then there's always the option of getting sport seats
