As long as you pay less than what you are willing to pay, you obtain consumer surplus. I would expect complementary goods to increase your consumer surplus as you have more reason to own something. For example, if several really great PS4 games are released. Your willingness to pay for a PS4 console will increase. If the price of the PS4 console remains the same, you will obtain a higher consumer surplus than before the release of the new games.

The availability of substitutes reduces our consumer surplus as we have an option to obtain something else similar. Therefore, our willingness to pay falls and so does our consumer surplus.